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NLE Immune System & Immunologic Disorders — Autoimmune Disorders and HIV/AIDSDetailed Explanation

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Detailed explanation of Autoimmune Disorders and HIV/AIDS for the NLE 2026. Full depth, full reasoning — exactly what you need when Professional Regulation Commission (PRC) — Board of Nursing tests this chapter with applied or scenario-based questions in the NLE Immune System & Immunologic Disorders subtest.

Exam context

The Philippine Nurse Licensure Examination (PNLE) is conducted by Professional Regulation Commission (PRC) — Board of Nursing and is scheduled for Bi-annual. The Immune System & Immunologic Disorders subtest is marked as "Core" in the official pattern, and Autoimmune Disorders and HIV/AIDS appears in position 2nd of 2 in the NLE Immune System & Immunologic Disorders review rotation. Passing mark: 75% weighted average with no sub-test below 60%. Recent NLE 2026 papers have drawn roughly 50 questions from this subject.

Immunity, Hypersensitivity and Allergic Disorders - Detailed Explanation

The immune system is the body's defense force — it recognizes, attacks, and eliminates threats such as bacteria, viruses, foreign proteins, and abnormal cells. For the NLE, understanding how this system works is critical not only for theory questions but also for clinical decision-making in nursing practice. This chapter covers the essential concepts of innate vs. adaptive immunity, the five classes of immunoglobulins, the four types of hypersensitivity reactions, the emergency management of anaphylaxis, latex allergy, and immunodeficiency disorders. In Philippine clinical settings — from barangay health centers to tertiary hospitals — nurses must be able to recognize allergic emergencies, administer epinephrine correctly, educate patients about allergen avoidance, and implement protective precautions for immunocompromised patients. Under RA 9173 (Philippine Nursing Act of 2002), the nurse is mandated to practice with competence, and that includes the ability to respond appropriately in life-threatening allergic emergencies. Master this chapter, and you master one of the NLE's most frequently tested clinical topics.

Concepts

Overview of Immunity: Innate vs. Adaptive

Immunity is the body's capacity to resist and defend against foreign substances called antigens. Think of it as a two-layer security system. The first layer is innate (natural, nonspecific) immunity — it is present from birth, responds immediately and in the same way to any invader, has no memory, and includes physical barriers (skin, mucous membranes), phagocytic cells (neutrophils, macrophages), the complement system, and the inflammatory response. The second layer is adaptive (acquired, specific) immunity — it is antigen-specific, develops over days to weeks, and most importantly, creates immunological memory so the response is faster and stronger on re-exposure. Adaptive immunity has two arms: (1) Humoral immunity, mediated by B lymphocytes (B cells) that differentiate into plasma cells and produce antibodies (immunoglobulins); and (2) Cell-mediated immunity, mediated by T lymphocytes (T cells) — specifically Helper T cells (CD4+) that coordinate the immune response and Cytotoxic T cells (CD8+) that kill infected or abnormal cells directly. The easiest way to remember: innate = first responder (fast, non-specific, no memory); adaptive = specialized unit (slow, specific, has memory).

Examples

This illustrates the principle of immunological memory — the hallmark of adaptive immunity. This is also the scientific basis for vaccination.

Scenario

A 25-year-old student contracts chickenpox for the first time. The adaptive immune response is activated. Two years later, the same student is exposed to the chickenpox virus again.

Solution

On first exposure: B cells produce IgM first (primary response), then IgG. Memory B and T cells are formed. On re-exposure: memory cells rapidly proliferate and produce large amounts of IgG — the secondary (anamnestic) response. The student does not get sick again because the virus is eliminated before it can cause disease.

Redness (rubor), warmth (calor), swelling (tumor), and pain (dolor) are the classic signs of inflammation — a hallmark of innate immune response. Phagocytes are recruited to the site to eliminate the threat.

Scenario

A nurse notices that a patient recovering from a motor vehicle accident has an intact skin but develops a localized redness, warmth, and swelling at the wound site.

Solution

This is the inflammatory response — part of innate immunity. It is a nonspecific defense mechanism triggered by tissue injury or infection.

Applications

  • Understanding innate immunity helps explain why fever, redness, and swelling are protective responses — the nurse should not always try to suppress them unless harmful
  • Knowledge of adaptive immunity underpins vaccination programs in the Philippine Expanded Program on Immunization (EPI)
  • CD4+ T cell counts guide HIV/AIDS management in Philippine DOH treatment hubs
  • Nursing assessment of immunocompromised patients must focus on subtle infection signs since their innate and adaptive responses may both be impaired

Misconceptions

  • Misconception: The inflammatory response is harmful and should always be suppressed. Fact: Inflammation is a protective innate immune response; it becomes harmful only when excessive or chronic.
  • Misconception: All immunity is provided by antibodies. Fact: Cell-mediated immunity (T cells) is equally important — it is the primary defense against intracellular pathogens like Mycobacterium tuberculosis and viruses.
  • Misconception: Innate and adaptive immunity work independently. Fact: They work together — innate immunity activates adaptive immunity by presenting antigens to T cells.

Related Concepts

  • Types of Acquired Immunity (Active vs. Passive)
  • Immunoglobulin Classes
  • Immunodeficiency Disorders
  • HIV/AIDS Nursing Management

Common Exam Questions

Example

Which component of the immune system is responsible for the immediate inflammatory response to a bee sting? (Answer: Innate immunity — complement system and mast cell degranulation)

Approach

The NLE will ask you to identify whether a given scenario demonstrates innate or adaptive immunity. Key clue: Is the response specific to a particular antigen? Does it involve memory? If yes — adaptive. Is it immediate and nonspecific? Innate.

Question Type

Identification/Classification

Example

A patient with HIV/AIDS has a CD4+ count of 150 cells/mm³. The nurse should anticipate orders for prophylactic medications against which organisms? (Answer: Pneumocystis jirovecii pneumonia prophylaxis — trimethoprim-sulfamethoxazole)

Approach

Questions about why a patient with HIV is vulnerable to opportunistic infections require understanding that HIV destroys CD4+ helper T cells, crippling both humoral and cell-mediated adaptive immunity.

Question Type

Application/Clinical judgment

Key Points To Remember

  • Innate immunity is nonspecific, immediate, and has NO memory — it responds the same every time
  • Adaptive immunity is antigen-specific, slower to develop, but creates MEMORY for faster future responses
  • Humoral immunity = B cells → plasma cells → antibodies (immunoglobulins)
  • Cell-mediated immunity = T cells (CD4+ helper and CD8+ cytotoxic)
  • CD4+ (helper T cells) are the cells destroyed by HIV — explaining the immunodeficiency in AIDS
  • Phagocytes (neutrophils, macrophages) are part of innate immunity
  • The complement system enhances (complements) antibody activity — part of innate immunity

Immunoglobulins (Antibody Classes)

Immunoglobulins (Ig) are proteins produced by plasma cells (mature B cells) that bind specifically to antigens to neutralize or mark them for destruction. There are five classes, each with distinct functions that are high-yield for the NLE. Think of the mnemonic **GAMED** or remember their functions by their location and timing. IgG (the most abundant, ~75% of serum antibodies) is the workhorse of the secondary immune response and is the ONLY immunoglobulin that crosses the placenta, providing passive immunity to the newborn during the first months of life. IgM is the largest antibody and the FIRST produced in a primary (acute) infection — its presence indicates a current or very recent infection; it does NOT cross the placenta. IgA is the secretory antibody found in body fluids — saliva, tears, colostrum, breast milk, and mucous membrane secretions — protecting mucosal surfaces; breast-fed infants receive IgA through breast milk. IgE is the allergy antibody — it binds to receptors on mast cells and basophils and triggers degranulation (release of histamine) when cross-linked by an allergen; it is central to type I (anaphylactic) hypersensitivity and mediates asthma, hay fever, hives, and anaphylaxis. IgD functions primarily as an antigen receptor on the surface of naive B cells; its clinical significance is least understood and least tested.

Examples

IgM elevation = acute infection. IgG elevation (in the same context) would indicate past infection or immunity (from prior infection or vaccination).

Scenario

A serologic test for hepatitis A shows elevated IgM anti-HAV. The patient asks the nurse what this means.

Solution

Elevated IgM anti-HAV indicates a current or recent (acute) hepatitis A infection. IgM is the first antibody produced in a new infection.

IgG is the only immunoglobulin that crosses the placenta. This is why newborns have some protection against diseases their mothers are immune to, even before their own immune system matures.

Scenario

A 2-month-old infant whose mother had rubella immunity has not yet received the MMR vaccine. A serum test shows IgG antibodies against rubella.

Solution

The IgG is maternal — transferred across the placenta before birth. This is natural passive immunity and is temporary (lasting about 3–6 months after birth).

IgE is central to all immediate allergic reactions. Elevated serum total IgE and allergen-specific IgE (by RAST/ImmunoCAP) confirm an allergic etiology.

Scenario

A patient with a known peanut allergy accidentally eats food containing peanuts and immediately develops urticaria and bronchospasm.

Solution

This is a Type I IgE-mediated hypersensitivity reaction. The patient was previously sensitized to peanut proteins; peanut-specific IgE is bound to mast cells. Re-exposure causes cross-linking of IgE → mast cell degranulation → histamine and leukotriene release → urticaria and bronchospasm.

Applications

  • Interpreting serologic tests: IgM = acute/current infection; IgG = past infection or immunity
  • Explaining to mothers why breastfeeding protects infants — IgA in breast milk provides mucosal immunity
  • Understanding why allergic patients have elevated serum IgE levels
  • Explaining to parents why newborns have some immunity initially (maternal IgG via placenta) but need vaccination later

Misconceptions

  • Misconception: All antibodies cross the placenta. Fact: Only IgG crosses the placenta; IgM, IgA, IgE, and IgD do not.
  • Misconception: High IgE is found only in anaphylaxis. Fact: IgE is elevated in any IgE-mediated allergy — hay fever, asthma, food allergy — not only in anaphylaxis.
  • Misconception: IgM persists long after an infection. Fact: IgM is short-lived; it declines as the primary response resolves. Persistent immunity is maintained by IgG memory.

Related Concepts

  • Type I Hypersensitivity and Anaphylaxis
  • Active vs. Passive Immunity
  • Immunodeficiency Disorders
  • Breastfeeding and Infant Immunity (NCM 101)

Common Exam Questions

Example

A patient with severe combined immunodeficiency (SCID) would have deficiency of which immunoglobulins? (Answer: All classes — both B cells and T cells are absent in SCID)

Approach

Match the immunoglobulin to its function or clinical finding. Use the unique features: IgG crosses placenta, IgM first in acute infection, IgA in secretions, IgE causes allergy.

Question Type

Identification

Example

A nurse is reviewing lab results for a patient suspected of having a new HIV infection. Which immunoglobulin marker would confirm an acute (window period) infection? (Answer: HIV RNA or p24 antigen — IgM and IgG antibodies appear later; this tests understanding that IgM appears first but the window period may precede detectable antibodies)

Approach

NLE may describe a clinical scenario and ask which immunoglobulin is responsible. Focus on IgE for allergy/anaphylaxis and IgM for acute infection interpretation.

Question Type

Clinical application

Key Points To Remember

  • IgG — most abundant; crosses the placenta (neonatal passive immunity); drives the secondary (memory) response
  • IgM — largest; FIRST antibody in primary infection; does NOT cross the placenta; its presence = acute/recent infection
  • IgA — found in secretions (saliva, tears, colostrum, breast milk); protects mucosal surfaces
  • IgE — mediates TYPE I hypersensitivity (allergy, anaphylaxis); binds mast cells and basophils; triggers histamine release
  • IgD — surface receptor on B cells; least clinically significant; rarely tested
  • Memory aid: 'IgE = Emergency allergy antibody'; 'IgM = iMMediate first responder in acute infection'; 'IgG = Goes across the placenta'

Types of Acquired Immunity: Active vs. Passive, Natural vs. Artificial

Acquired (adaptive) immunity can be classified by two questions: (1) Did the person make their own antibodies (active) or receive ready-made antibodies (passive)? (2) Was it acquired naturally (through biology) or artificially (through medical intervention)? This produces four types. Active immunity — whether natural (post-infection) or artificial (post-vaccination) — is SLOW to develop (days to weeks) but LONG-LASTING because B memory cells are created. Passive immunity — whether natural (maternal IgG via placenta, IgA via breast milk) or artificial (injection of immune serum/globulin) — is IMMEDIATE because the antibodies are already made, but TEMPORARY because no memory cells are formed and the borrowed antibodies eventually degrade. The golden rule: ACTIVE = slow but durable (memory); PASSIVE = fast but fleeting (no memory). For the NLE, you must know examples of each type — especially the difference between giving a vaccine (artificial active) and giving immunoglobulin (artificial passive), since these have different purposes and timings in post-exposure prophylaxis.

Examples

This is the classic NLE distinction: vaccine (active, stimulates own production) vs. immunoglobulin (passive, gives ready-made). The combination of both provides both immediate and long-term protection.

Scenario

A nurse in a Philippine community health center is preparing to give hepatitis B vaccine to a newborn. The mother asks: 'Is this the same as the hepatitis B injection given to baby after delivery if I am HBsAg positive?'

Solution

No — they are different. The hepatitis B vaccine (given to all newborns within 24 hours) is artificial ACTIVE immunity — the baby's immune system is stimulated to produce its own antibodies. If the mother is HBsAg-positive, the baby also receives Hepatitis B Immunoglobulin (HBIG) — this is artificial PASSIVE immunity, providing immediate ready-made antibodies to protect the baby while its own immunity develops.

In Philippine DOH protocol, rabies PEP combines passive (RIG) and active (vaccine) immunity. RIG is given only once — it would interfere with the vaccine response if given again. This is a real-world Philippine health scenario likely to appear in NLE community health questions.

Scenario

A farmer in Laguna is bitten by a dog suspected of rabies. He is brought to the rural health unit. What immunization protocol applies?

Solution

Post-exposure prophylaxis (PEP) for rabies involves: (1) Wound washing, (2) Rabies Immunoglobulin (RIG) infiltrated into and around the wound — artificial PASSIVE immunity for immediate protection, and (3) Rabies vaccine series (Day 0, 3, 7, 14, 28) — artificial ACTIVE immunity for lasting protection.

Applications

  • Philippine Expanded Program on Immunization (EPI) — all vaccines are artificial active immunity
  • Post-exposure prophylaxis for rabies, hepatitis B, and tetanus uses the passive-active combination
  • Newborn receives maternal IgG for the first 3–6 months — explaining why infants are given time before full vaccination series takes effect
  • IVIG (intravenous immunoglobulin) therapy for immunodeficiency patients — artificial passive immunity

Misconceptions

  • Misconception: Vaccines provide immediate protection. Fact: Vaccines (active immunity) take 2–4 weeks to generate protective antibody levels — this is why passive immunoglobulin is needed for immediate post-exposure protection.
  • Misconception: Passive immunity from the mother protects the infant indefinitely. Fact: Maternal IgG wanes by 3–6 months — this is why the vaccination schedule begins early in life.
  • Misconception: Having received a vaccine means you can never get the disease. Fact: Vaccine-induced immunity may wane over time (e.g., tetanus boosters every 10 years are needed); additionally, some individuals may not mount an adequate response (vaccine failure).

Related Concepts

  • Philippine Expanded Program on Immunization (EPI)
  • Immunoglobulin Classes (IgG placental transfer)
  • Post-exposure Prophylaxis Protocols
  • Immunodeficiency and IVIG Therapy

Common Exam Questions

Example

A child recovers from measles and is now immune. What type of immunity does this represent? (Answer: Natural active immunity — the child's own immune system produced antibodies and memory cells after the actual infection)

Approach

Read the scenario and ask: Did the person produce their own antibodies? → Active. Were ready-made antibodies given or transferred? → Passive. Was it from a natural process? → Natural. Was it medically administered? → Artificial.

Question Type

Classification/Identification

Example

A non-immune nurse is accidentally stuck with a needle from an HBsAg-positive patient. The immediate priority intervention is: (Answer: Administer HBIG — artificial passive immunity — for immediate protection; follow with hepatitis B vaccine series for active immunity)

Approach

NLE may ask when to use passive vs. active immunity. Passive is for immediate protection in unimmunized, exposed individuals. Active (vaccine) is for pre-exposure or long-term protection.

Question Type

Prioritization/Application

Key Points To Remember

  • Active immunity = body MAKES its own antibodies → slow onset, LONG-LASTING, creates memory
  • Passive immunity = body RECEIVES ready-made antibodies → IMMEDIATE onset, TEMPORARY, no memory
  • Natural active = infection (e.g., chickenpox, measles, hepatitis A recovery)
  • Artificial active = vaccination (e.g., MMR, hepatitis B vaccine, tetanus toxoid) — part of Philippine EPI
  • Natural passive = placental transfer of IgG; IgA in breast milk (colostrum)
  • Artificial passive = immunoglobulin injection: tetanus immunoglobulin (TIG), hepatitis B immunoglobulin (HBIG), rabies immunoglobulin (RIG), antivenom (for snakebite), varicella-zoster immunoglobulin
  • Post-exposure prophylaxis for rabies uses BOTH: RIG (passive, immediate protection) AND rabies vaccine (active, for long-term immunity)

The Four Types of Hypersensitivity Reactions (Gell and Coombs Classification)

Hypersensitivity is an exaggerated, inappropriate, or harmful immune response to an antigen that causes tissue damage to the host. The Gell and Coombs classification describes four types (I through IV). A simple memory aid is **ACID**: I = Anaphylactic, II = Cytotoxic, III = Immune complex, IV = Delayed. Types I, II, and III are all antibody-mediated (humoral) and generally rapid; Type IV is T-cell-mediated and characteristically delayed (24–72 hours). TYPE I (Anaphylactic/Allergic): Mediated by IgE. Sensitization occurs on first exposure (IgE is produced and binds to mast cells/basophils). Re-exposure causes antigen to cross-link the IgE on mast cells → degranulation → release of histamine, leukotrienes, prostaglandins → vasodilation, increased capillary permeability, bronchoconstriction, smooth muscle contraction. Occurs within MINUTES. Examples: anaphylaxis, allergic rhinitis, asthma, urticaria, food/drug allergy, latex allergy (immediate form). TYPE II (Cytotoxic): Mediated by IgG or IgM antibodies directed against antigens on the SURFACE of the patient's OWN cells. The antibody-antigen complex activates complement or phagocytosis → cell destruction. Examples: ABO-incompatible blood transfusion reaction (most tested!), hemolytic disease of the newborn (Rh incompatibility), autoimmune hemolytic anemia, immune thrombocytopenic purpura (ITP), Goodpasture syndrome, myasthenia gravis, Graves disease. TYPE III (Immune Complex): Soluble antigen-antibody complexes form in the circulation and deposit in tissues, vessel walls, kidneys, joints, and skin. Complement is activated → inflammation and tissue damage. Onset typically hours to days. Examples: SLE (systemic lupus erythematosus), rheumatoid arthritis, acute post-streptococcal glomerulonephritis, serum sickness, Arthus reaction. TYPE IV (Delayed/Cell-Mediated): The ONLY type NOT mediated by antibodies. Sensitized T lymphocytes react with the antigen and release cytokines (lymphokines) that recruit macrophages → inflammation. Onset is 24–72 HOURS after re-exposure. Examples: PPD/Mantoux tuberculin skin test reaction (positive = Type IV), contact dermatitis (poison ivy, nickel, latex delayed reaction), transplant/graft rejection, granulomatous disease (TB, sarcoidosis).

Examples

STOP the transfusion immediately, maintain IV access with normal saline, notify the physician and blood bank, monitor urine output (renal failure risk from hemoglobin precipitation in tubules). This is a priority nursing action for transfusion reactions.

Scenario

A nurse administers a unit of blood. Within 15 minutes, the patient develops fever, chills, back pain, hemoglobinuria (red-colored urine), and hypotension. What type of hypersensitivity reaction is this?

Solution

This is a Type II (cytotoxic) hypersensitivity — specifically an acute hemolytic transfusion reaction due to ABO incompatibility. IgM antibodies in the recipient's plasma attack the donor red blood cells → complement activation → intravascular hemolysis.

A positive Mantoux (induration ≥10 mm for most Filipinos; ≥5 mm for immunocompromised) indicates prior sensitization to M. tuberculosis — NOT necessarily active disease. This is a critical NLE distinction.

Scenario

A 30-year-old patient received a Mantoux (PPD) tuberculin test. After 48 hours, the nurse reads an induration of 15 mm at the injection site. What type of hypersensitivity reaction is this?

Solution

This is Type IV (delayed) hypersensitivity. Sensitized T lymphocytes from prior TB exposure recognize the purified protein derivative (PPD) antigen and release cytokines that recruit macrophages → induration (hardening) at the site after 24–72 hours.

SLE is the classic Type III disorder. The lupus nephritis (proteinuria, hematuria) is caused by immune complex deposition in the glomerular basement membrane.

Scenario

A patient with SLE presents with butterfly rash, proteinuria, and joint pain. Which type of hypersensitivity is the primary mechanism?

Solution

Type III — Immune complex hypersensitivity. In SLE, autoantibodies (anti-dsDNA, anti-Smith) form immune complexes with self-antigens that deposit in glomeruli, skin, and joints → complement activation → inflammation and tissue damage.

Applications

  • Type I: Anaphylaxis emergency management — epinephrine is priority
  • Type II: Blood transfusion monitoring — stop transfusion immediately if hemolytic reaction suspected
  • Type II: Rh incompatibility management — administer RhoGAM (Rh immunoglobulin) to Rh-negative mothers after delivery or potential sensitization events
  • Type III: SLE and glomerulonephritis nursing care — monitor renal function, blood pressure, and urine output
  • Type IV: Contact precautions and wound care for patients with severe contact dermatitis; reading and interpreting Mantoux test results correctly in Philippine TB control programs

Misconceptions

  • Misconception: All allergic reactions are Type I. Fact: Contact dermatitis (e.g., to latex or nickel) is Type IV — it is T-cell mediated and delayed, not IgE-mediated.
  • Misconception: A positive Mantoux test means the patient has active TB. Fact: A positive Mantoux (PPD) indicates sensitization (prior exposure or BCG vaccination), NOT necessarily active disease — chest X-ray and sputum culture are needed for active TB diagnosis.
  • Misconception: Antihistamines are first-line for all hypersensitivity reactions. Fact: Antihistamines are only useful for Type I reactions and even in Type I anaphylaxis, epinephrine — NOT antihistamines — is the first-line life-saving drug.
  • Misconception: Type IV hypersensitivity is less dangerous than Type I. Fact: Type IV includes transplant rejection and granulomatous diseases, which can be life-threatening if untreated.

Related Concepts

  • Anaphylaxis Emergency Management
  • Blood Transfusion Reactions (NCM 104)
  • SLE Nursing Care
  • Tuberculosis and Mantoux Test Interpretation
  • Latex Allergy

Common Exam Questions

Example

Contact dermatitis that develops 48 hours after wearing a nickel-plated necklace is which type of hypersensitivity? (Answer: Type IV — Delayed, T-cell mediated)

Approach

Match the clinical scenario to the hypersensitivity type using ACID. Key identifiers: minutes onset + IgE = Type I; cell destruction + IgG/IgM = Type II; immune complex deposits + hours-days = Type III; 24–72 hours + T cells + no antibody = Type IV.

Question Type

Identification

Example

A patient receiving a blood transfusion develops back pain, chills, and dark urine. The nurse's FIRST action is: (Answer: Stop the transfusion immediately and keep the IV line open with normal saline)

Approach

When a transfusion reaction occurs → STOP transfusion first. When anaphylaxis occurs → administer epinephrine first.

Question Type

Priority nursing action

Key Points To Remember

  • Memory aid ACID: I=Anaphylactic, II=Cytotoxic, III=Immune complex, IV=Delayed
  • Type I = IgE mediated; immediate (minutes); mast cell degranulation; histamine release
  • Type II = IgG or IgM vs. cell-surface antigens; cell destruction; ABO transfusion reaction is the classic example
  • Type III = immune complex deposition; complement activation; SLE and post-strep glomerulonephritis are classic examples
  • Type IV = T-cell mediated ONLY (no antibody); delayed 24–72 hours; PPD/Mantoux test is the classic example
  • Types I, II, III = antibody-mediated (can be transferred passively via serum); Type IV = T-cell mediated (transferred only by T cells)
  • The ABO transfusion reaction (Type II) is the most commonly tested clinical application of hypersensitivity in transfusion nursing

Anaphylaxis: Emergency Recognition and Management

Anaphylaxis is the most severe form of Type I IgE-mediated hypersensitivity — a life-threatening systemic allergic emergency that can kill within minutes. It is the single most heavily tested emergency in the NLE immunology section. Pathophysiology: Massive, rapid release of histamine and other mediators (leukotrienes, prostaglandins) from mast cells and basophils causes: (1) widespread vasodilation → sudden drop in systemic vascular resistance → distributive shock → profound HYPOTENSION; (2) increased capillary permeability → fluid shifts out of vessels → further hypotension and angioedema; (3) bronchoconstriction + laryngeal edema → airway obstruction. The leading cause of DEATH in anaphylaxis is AIRWAY OBSTRUCTION from laryngeal edema — not the hypotension. Common triggers: medications (penicillin is the classic — ask about drug allergies before EVERY injection!), foods (peanuts, shellfish, eggs, milk, tree nuts), insect venom (bee/wasp), latex, radiocontrast media, and blood products. CLINICAL MANIFESTATIONS (onset seconds to minutes after exposure): Early — sense of impending doom, pruritus (itching), flushing, urticaria (hives), angioedema (swelling of lips, tongue, face, eyelids). Progressing — throat tightness, hoarseness, stridor, wheezing, dyspnea, bronchospasm, chest tightness, tachycardia, hypotension, dizziness, syncope, cardiovascular collapse. EMERGENCY NURSING MANAGEMENT — PRIORITY ORDER: (1) EPINEPHRINE FIRST AND IMMEDIATELY — Adult dose: 0.3–0.5 mg (0.3–0.5 mL) of 1:1000 concentration (= 1 mg/mL) IM into the ANTEROLATERAL THIGH (vastus lateralis muscle). Pediatric dose: 0.01 mg/kg IM up to 0.3 mg maximum. Repeat every 5–15 minutes if needed. Epinephrine is the ONLY drug that simultaneously: bronchodilates (opens the airway), vasoconstricts (raises BP), reduces laryngeal edema, and blocks further mediator release. (2) Maintain AIRWAY — position properly, administer high-flow oxygen (100% via non-rebreather mask at 10–15 L/min), prepare for intubation or emergency cricothyrotomy if airway is obstructing. (3) REMOVE/STOP the trigger — stop IV drug infusion, stop blood transfusion, remove bee stinger. (4) POSITION — supine with legs ELEVATED (Trendelenburg or legs elevated 10–15°) to support venous return and blood pressure. EXCEPTION: If the patient has severe dyspnea/bronchospasm, allow semi-Fowler's position to ease breathing. (5) IV ACCESS and FLUIDS — establish large-bore IV access; infuse rapid isotonic crystalloids (0.9% NaCl/normal saline) for hypotension. (6) ADJUNCT MEDICATIONS (secondary — never first-line): Diphenhydramine (antihistamine — H1 blocker) 25–50 mg IV/IM; H2 blocker (famotidine or ranitidine) IV; Corticosteroids (hydrocortisone 200–300 mg IV or methylprednisolone) to prevent late-phase/biphasic reaction; Nebulized salbutamol (albuterol) for bronchospasm. (7) CONTINUOUS MONITORING — vital signs, SpO2, cardiac rhythm; BIPHASIC REACTION can occur 1–72 hours after apparent recovery — patient MUST be observed for at least 4–8 hours. CRITICAL NLE DRUG DISTINCTION: Epinephrine 1:1000 (1 mg/mL) = IM use for anaphylaxis. Epinephrine 1:10,000 (0.1 mg/mL) = IV use for CARDIAC ARREST. NEVER confuse these concentrations — administering the wrong concentration IV can be fatal.

Examples

This is a Philippine clinical scenario — penicillin anaphylaxis in a hospital setting. The NLE will test the sequence of priorities. EPINEPHRINE is always the first drug administered. The nurse must not delay to get antihistamines first. Under RA 9173, the nurse has the legal and professional duty to recognize and respond to this emergency competently.

Scenario

Nurse Ana has just administered 600,000 units of Penicillin G IM to a patient in a Philippine public hospital. Within 3 minutes, the patient reports throat tightness, develops hives all over the trunk, and suddenly becomes pale and diaphoretic. BP drops to 80/50 mmHg.

Solution

This is anaphylaxis — an immediate, life-threatening Type I hypersensitivity to penicillin. Priority actions: (1) Call for help/CODE TEAM; (2) Administer EPINEPHRINE 0.5 mg (1:1000) IM into the anterolateral thigh IMMEDIATELY; (3) Position supine with legs elevated (if no dyspnea); (4) Administer high-flow O2 via non-rebreather mask; (5) Establish or maintain IV access with large-bore catheter; (6) Infuse NS rapidly for hypotension; (7) Prepare adjuncts: diphenhydramine, hydrocortisone, salbutamol nebulization; (8) Continuously monitor vital signs and SpO2.

The patient must be observed for at least 4–8 hours after apparent recovery. In severe anaphylaxis, 24-hour observation in a hospital setting is recommended. This is important patient education and a common NLE scenario.

Scenario

A community health nurse has administered an anaphylaxis treatment and the patient recovers. The patient wants to go home after 30 minutes. The nurse insists on continued observation. Why?

Solution

Biphasic anaphylaxis — a recurrence of anaphylactic symptoms hours (typically 1–8 hours, rarely up to 72 hours) after the initial episode resolves, even without further allergen exposure. This occurs in approximately 5–20% of anaphylaxis cases.

Applications

  • Pre-injection nursing assessment: ALWAYS ask and document allergy history before giving ANY medication, especially antibiotics — this is a nursing standard under RA 9173
  • Emergency drug tray preparation: epinephrine, diphenhydramine, hydrocortisone, oxygen, salbutamol nebule must be available wherever injections are given
  • Patient education on epinephrine auto-injector (EpiPen) use for known high-risk patients
  • Anaphylaxis drill/simulation in Philippine hospitals — nurses must be prepared to act within 30–60 seconds
  • Accurate documentation of reactions and notification of physician per Philippine nursing standards

Misconceptions

  • Misconception: Antihistamines (diphenhydramine) should be given first for anaphylaxis because 'it is allergic.' Fact: Antihistamines block histamine receptors but cannot reverse laryngeal edema, bronchospasm, or shock — only epinephrine can do all three simultaneously. Antihistamines take 15–30 minutes to act — too slow for anaphylaxis.
  • Misconception: Epinephrine should be given IV first for faster effect. Fact: For anaphylaxis (not cardiac arrest), epinephrine is given IM into the anterolateral thigh — IM has faster, more reliable absorption in anaphylaxis than subcutaneous. IV epinephrine is only for cardiac arrest or when IM has failed with ongoing cardiovascular collapse.
  • Misconception: Once the patient recovers from anaphylaxis, they are safe to go home. Fact: Biphasic reaction risk requires 4–8 hours minimum observation — mandatory patient education.
  • Misconception: Corticosteroids are the most important drug in anaphylaxis because they 'treat inflammation.' Fact: Corticosteroids take hours to days to act and are used to PREVENT the late-phase biphasic reaction — they have no role in the immediate life-threatening phase.

Related Concepts

  • Type I Hypersensitivity
  • IgE and Mast Cell Degranulation
  • Latex Allergy
  • Allergic Disorders
  • Epinephrine Pharmacology
  • Shock Management (Distributive/Anaphylactic)

Common Exam Questions

Example

A patient develops severe urticaria, hoarseness, and BP of 70/40 mmHg after receiving IV contrast dye. The nurse's PRIORITY action is: A) Administer diphenhydramine IV B) Administer epinephrine 0.5 mg IM C) Elevate the head of the bed D) Administer hydrocortisone IV (Answer: B — Epinephrine IM is the priority first-line drug)

Approach

Always select EPINEPHRINE as the first intervention in anaphylaxis. If the question asks about airway management, the answer is still epinephrine first (because epinephrine addresses BOTH the airway via bronchoconstriction reversal and BP via vasoconstriction). Then maintain airway with O2.

Question Type

Priority action (most common NLE format)

Example

For an anaphylaxis emergency, the nurse prepares epinephrine 0.3 mg from a 1:1000 solution. How many mL should the nurse draw? (Answer: 1:1000 = 1 mg/mL; 0.3 mg ÷ 1 mg/mL = 0.3 mL)

Approach

Know that 1:1000 = 1 mg/mL (IM for anaphylaxis) and 1:10,000 = 0.1 mg/mL (IV for cardiac arrest). The NLE may ask which concentration is used for anaphylaxis or require you to calculate the volume to draw.

Question Type

Drug calculation/concentration identification

Key Points To Remember

  • Anaphylaxis = Type I IgE-mediated emergency; distributive shock + laryngeal edema = life-threatening
  • LEADING CAUSE OF DEATH in anaphylaxis = AIRWAY OBSTRUCTION from laryngeal edema (NOT hypotension)
  • FIRST-LINE DRUG = EPINEPHRINE IM (not IV for anaphylaxis) 0.3–0.5 mg of 1:1000 in anterolateral thigh
  • Pediatric epinephrine dose = 0.01 mg/kg IM (max 0.3 mg)
  • Epinephrine 1:1000 → IM for anaphylaxis; Epinephrine 1:10,000 → IV for cardiac arrest — DO NOT CONFUSE
  • Antihistamines and corticosteroids are ADJUNCTS only — too slow to prevent death — NEVER first-line
  • Biphasic reaction can occur 1–72 hours after initial recovery — observe patient for minimum 4–8 hours
  • ALWAYS ask about drug allergies before any injection — penicillin is the classic cause of drug-induced anaphylaxis
  • Patient teaching: carry epinephrine auto-injector (EpiPen) at all times; wear medical-alert bracelet; avoid known allergens; seek emergency care after every use

Allergic Disorders

Allergic disorders are conditions caused by Type I IgE-mediated hypersensitivity to ordinarily harmless environmental substances called allergens. They range from mild (seasonal rhinitis) to life-threatening (anaphylaxis). Common allergens in the Philippine setting include house dust mites (very prevalent in humid tropical climate), mold spores, animal dander, cockroach allergens, pollen, foods (peanuts, shellfish — very common food allergy in Filipinos, eggs, milk), insect venom, medications (penicillin, aspirin, NSAIDs, sulfonamides), and latex. ASSESSMENT — A comprehensive allergy history is the most critical nursing assessment: What is the specific allergen? What symptoms occur? How quickly? How severe? Have there been prior reactions and what happened? What medications are currently taken? Allergen assessment must be performed before EVERY medication administration. CLINICAL MANIFESTATIONS by system: Respiratory — sneezing, rhinorrhea (runny nose), nasal congestion, itchy/watery eyes (allergic rhinoconjunctivitis/hay fever); wheezing, chest tightness, dyspnea (allergic asthma). Skin — urticaria (hives: raised, erythematous, intensely pruritic wheals), angioedema (deep tissue swelling of lips, tongue, face, eyelids — airway threat!), pruritus, erythema. GI — nausea, vomiting, cramping, diarrhea (especially food allergy). Eyes — itching, tearing, conjunctival injection. DIAGNOSTIC TESTS: (1) Skin testing (scratch/prick test or intradermal test) — a wheal-and-flare response indicates sensitization; ALWAYS have emergency equipment (epinephrine, oxygen) available during skin testing because of anaphylaxis risk. (2) Serum total IgE — elevated in atopic individuals. (3) Allergen-specific IgE (RAST/ImmunoCAP) — identifies specific allergen sensitization from blood — safer than skin testing for high-risk patients. (4) CBC with differential — eosinophilia (elevated eosinophil count) supports allergic etiology. PHARMACOLOGIC MANAGEMENT: Antihistamines (H1 blockers) — first-line for mild to moderate allergic symptoms. First generation (diphenhydramine/Benadryl): sedating, anticholinergic (dry mouth, urinary retention, constipation); caution in elderly, those driving, BPH. Second generation (cetirizine/loratadine/fexofenadine): minimally sedating, preferred for daytime use. Corticosteroids (prednisone oral; fluticasone intranasal) — for moderate-severe or chronic allergy; NEVER stop systemic steroids abruptly (adrenal suppression). Mast cell stabilizers (cromolyn sodium) — prophylactic only; prevents mast cell degranulation; must be taken before allergen exposure. Leukotriene modifiers (montelukast/Singulair) — for allergic asthma and rhinitis; blocks leukotriene receptor; taken daily. Decongestants (pseudoephedrine) — relieves nasal congestion; CONTRAINDICATED in hypertension, cardiac disease, glaucoma. Allergen immunotherapy (allergy shots/SLIT) — gradual desensitization by repeated small antigen exposure — modifies the immune response long-term.

Examples

Second-generation antihistamines are preferred for outpatient use because they minimize sedation, allowing patients to drive and work normally — a common NLE pharmacology application.

Scenario

A patient in an OPD clinic reports seasonal sneezing, watery itchy eyes, and nasal congestion — worsening during ambon (misty weather) and when near flowering plants. The physician prescribes loratadine.

Solution

This is allergic rhinoconjunctivitis (hay fever) — Type I IgE-mediated allergy to pollen/mold. Loratadine is a second-generation antihistamine — less sedating, once-daily dosing. Patient teaching: take consistently during allergy season, avoid known triggers, use saline nasal irrigation, consider intranasal corticosteroids for better control.

Skin allergy testing — especially intradermal testing with concentrated allergens — can trigger systemic reactions. The nurse's duty is preparedness for emergency response. This aligns with nursing competency standards under RA 9173.

Scenario

A nurse is assisting in an allergy clinic where a patient is about to undergo intradermal skin testing for bee venom allergy. What preparation should the nurse ensure?

Solution

Ensure emergency anaphylaxis equipment is immediately available: epinephrine 1:1000 in syringe ready for IM injection, oxygen with non-rebreather mask, IV access supplies, diphenhydramine, and corticosteroids. Assess patient baseline vital signs. Monitor the patient continuously during and after testing for at least 30 minutes.

Applications

  • Allergy documentation: Use a standardized allergy band in Philippine hospitals; document allergen and type of reaction clearly
  • Medication reconciliation: verify allergy status at every healthcare encounter — especially before antibiotic administration
  • Patient education for atopic (allergic) individuals: allergen avoidance, proper inhaler technique, antihistamine timing
  • Community health: educating Filipino families about common food allergens (shellfish is a very common Filipino food — allergy education is critical)
  • School nursing: managing children with known food allergies, epinephrine auto-injector protocols

Misconceptions

  • Misconception: Urticaria (hives) is always benign and does not require urgent attention. Fact: Urticaria can be the first sign of anaphylaxis — always assess for systemic symptoms (hypotension, dyspnea, laryngeal edema) when hives appear after allergen exposure.
  • Misconception: Cromolyn sodium can be used to treat an acute allergic attack. Fact: Cromolyn is a prophylactic agent that must be taken BEFORE allergen exposure; it has no role in treating an already-occurring reaction.
  • Misconception: Antihistamines can be stopped suddenly without consequence. Fact: While antihistamines do not cause physical dependence, abrupt cessation of corticosteroids (often given with antihistamines for allergy) can cause adrenal crisis — the distinction is important.

Related Concepts

  • Anaphylaxis Management
  • Type I Hypersensitivity
  • Latex Allergy
  • Allergic Asthma Nursing Care
  • IgE and Mast Cell Degranulation

Common Exam Questions

Example

A patient with allergic rhinitis and hypertension asks about using an over-the-counter decongestant nasal spray with pseudoephedrine. The nurse's response should be: (Answer: Advise against it — pseudoephedrine is a sympathomimetic that can elevate blood pressure; recommend saline nasal irrigation or intranasal corticosteroids as safer alternatives)

Approach

Know the side effects of each allergy drug class. Diphenhydramine = sedation + anticholinergic. Pseudoephedrine = hypertension risk. Corticosteroids = do not stop abruptly.

Question Type

Drug adverse effect/contraindication

Example

A patient with a known bee allergy is stung and develops both urticaria and hoarseness. The nurse's PRIORITY concern is: (Answer: Hoarseness — it suggests developing laryngeal edema/angioedema, an airway emergency; epinephrine administration is priority)

Approach

Always prioritize airway-related allergic symptoms (angioedema, stridor, throat tightness) over skin or GI symptoms when determining nursing priority.

Question Type

Assessment priority

Key Points To Remember

  • Allergy history is the MOST important nursing assessment before ANY medication administration
  • Angioedema of the tongue or throat = AIRWAY EMERGENCY — requires immediate action
  • Emergency equipment MUST be available during skin allergy testing — anaphylaxis can occur
  • First-generation antihistamines (diphenhydramine) = sedating + anticholinergic; second-generation (cetirizine, loratadine) = less sedating
  • Corticosteroids: NEVER stop abruptly — gradual tapering required to prevent adrenal crisis
  • Cromolyn sodium is PROPHYLACTIC only — ineffective once a reaction has started
  • Pseudoephedrine is contraindicated in hypertension (elevates blood pressure)
  • Eosinophilia on CBC supports an allergic or parasitic process
  • Allergen-specific IgE (RAST) is safer than skin testing for highly allergic patients

Latex Allergy

Latex allergy is an immune response to natural rubber latex (NRL), derived from the sap of the Hevea brasiliensis tree — the same tree used to produce rubber gloves, catheters, balloons, and other medical equipment widely used in Philippine hospitals. Its importance in nursing cannot be overstated because healthcare workers are one of the highest-risk groups. Latex allergy presents in TWO distinct forms: FORM 1 — Type IV Delayed Contact Dermatitis (most common form): This is a T-cell mediated (delayed hypersensitivity) reaction to CHEMICAL ADDITIVES used in manufacturing rubber gloves, not to the latex protein itself. Presents as eczematous, pruritic, erythematous rash on hands 24–48 hours after latex contact. Onset is delayed — not immediately dangerous but is the most common occupational skin disorder among health workers. FORM 2 — Type I Immediate IgE-Mediated Reaction (the dangerous form): This is a true IgE-mediated allergy to LATEX PROTEINS. Onset is within minutes of contact. Symptoms range from urticaria and rhinitis to asthma, angioedema, and potentially ANAPHYLAXIS. This can be triggered by direct contact with latex (gloves, condom, catheter) or even AEROSOLIZED latex particles from powdered gloves — inhalation can trigger severe respiratory reactions. AT-RISK POPULATIONS: (1) Healthcare workers (repeated glove exposure); (2) Patients with SPINA BIFIDA — classic high-risk group because they undergo multiple surgeries and catheterizations from birth (highest prevalence of latex allergy, ~40–65%); (3) Patients with multiple prior surgeries; (4) Workers with heavy occupational latex exposure (factory workers, dental personnel); (5) Individuals with atopy (hay fever, asthma, eczema). LATEX-FOOD CROSS-REACTIVITY: Latex proteins cross-react with certain foods — the classic list is ABCK: Avocado, Banana, Chestnut (kastanyas), Kiwi. Also: tomato, potato, papaya. These patients may develop oral allergy syndrome or systemic reactions to these foods. NURSING MANAGEMENT: (1) IDENTIFY at-risk patients on ADMISSION — include in nursing assessment and allergy history; (2) Designate a LATEX-FREE ENVIRONMENT — use only non-latex (nitrile or vinyl) gloves, non-latex catheters, IV tubing, blood pressure cuffs, and equipment; (3) SCHEDULE latex-sensitive surgical patients as the FIRST CASE OF THE DAY — to minimize cumulative aerosolized latex particles in the OR environment (latex settles overnight); (4) Label the patient's room, chart, and wristband with 'Latex Allergy'; (5) Keep emergency anaphylaxis supplies available; (6) Educate patient to inform all healthcare providers, dentists, and to avoid latex products in daily life.

Examples

Spina bifida patients are at 40–65% prevalence of latex allergy due to lifetime repeated catheterizations. The nurse's proactive assessment is a legal and ethical duty under RA 9173. Failure to identify latex allergy can result in intraoperative anaphylaxis — which is more difficult to manage than in a ward setting.

Scenario

A nurse assigned to the OR preoperative assessment unit is caring for a 12-year-old patient with spina bifida scheduled for a urologic surgery. The patient's chart does not mention latex allergy. What should the nurse do?

Solution

The nurse should proactively SCREEN for latex allergy given the patient's high-risk status (spina bifida). Ask: Does the patient have reactions when using rubber gloves, blowing up balloons, or during prior surgeries? Does the patient have reactions to avocado, banana, kiwi, or chestnut? A positive history requires immediate latex-free precautions and scheduling the patient as the first case of the day.

Healthcare workers with persistent hand dermatitis related to latex should be evaluated and switched to alternative gloves. Importantly, Type IV latex contact dermatitis can progress to Type I sensitization — making early intervention important for long-term safety.

Scenario

A staff nurse in a Philippine government hospital develops a red, itchy, scaly rash on both hands every day after 12-hour shifts using latex gloves. Symptoms resolve on days off.

Solution

This is likely Type IV delayed contact dermatitis to latex or rubber glove additives. Onset 24–48 hours after exposure, resolves with avoidance. Management: switch to nitrile or vinyl non-powdered gloves; refer to dermatology/occupational health; document as a workplace health concern.

Applications

  • Preoperative nursing assessment must include latex allergy screening for all surgical patients, especially those with spina bifida or multiple prior surgeries
  • Philippine hospital infection control policy should include latex allergy protocols and stock of non-latex alternatives
  • Occupational health nursing: monitor healthcare workers for latex sensitization; recommend nitrile gloves
  • Patient education: avoid latex balloons, latex condoms (use polyurethane/polyisoprene alternatives), inform all providers including dentists
  • Emergency preparedness: latex-free code cart and anaphylaxis equipment in all patient care areas

Misconceptions

  • Misconception: Only patients who have had an immediate reaction to latex are at risk for anaphylaxis. Fact: Type IV contact dermatitis can progress to Type I IgE-mediated sensitization — patients with chronic latex contact dermatitis should be screened for systemic IgE sensitization.
  • Misconception: Latex allergy only occurs from direct skin contact with latex. Fact: Aerosolized latex particles from powdered gloves can trigger serious respiratory and systemic reactions in sensitized individuals without direct contact.
  • Misconception: Latex allergy is rare and not important in Philippine clinical practice. Fact: With widespread latex glove use in Philippine hospitals, latex allergy is a significant occupational and patient safety concern.

Related Concepts

  • Type I and Type IV Hypersensitivity
  • Anaphylaxis Management
  • Occupational Health Nursing
  • Surgical Nursing Perioperative Care (NCM 104)

Common Exam Questions

Example

Which patient is at HIGHEST risk for latex allergy? A) A 30-year-old with hay fever B) A 5-year-old with spina bifida C) A nurse who has used gloves for 2 years D) A patient with asthma (Answer: B — spina bifida patients have the highest prevalence of latex allergy due to repeated catheterizations and surgeries from infancy)

Approach

Know that spina bifida = highest risk for latex allergy. Multiple prior surgeries, healthcare workers, and atopic individuals are also high risk.

Question Type

Identification of high-risk patient

Example

To reduce the risk of anaphylaxis in a latex-sensitive patient scheduled for surgery, the most important nursing action specific to OR scheduling is: (Answer: Schedule the patient as the FIRST CASE OF THE DAY — aerosolized latex particles settle overnight; morning schedule minimizes airborne latex exposure)

Approach

Know the specific intervention of scheduling latex-sensitive patients first in the OR — this is a specific, frequently tested action.

Question Type

Nursing intervention

Key Points To Remember

  • Two forms: Type IV delayed contact dermatitis (most common, less dangerous) and Type I immediate IgE-mediated reaction (dangerous — can cause anaphylaxis)
  • HIGHEST RISK GROUP: Patients with SPINA BIFIDA (multiple surgeries/catheterizations from birth)
  • Other high-risk: healthcare workers, patients with multiple prior surgeries, atopic individuals
  • Latex-food cross-reactivity: Avocado, Banana, Chestnut, Kiwi (ABCK) — also tomato, potato, papaya
  • Aerosolized latex from powdered gloves can trigger reactions in sensitive individuals even without direct contact
  • Schedule latex-allergic patients as FIRST CASE OF THE DAY in the OR
  • Use latex-free environment: nitrile or vinyl gloves, non-latex medical equipment
  • Label patient chart, room, and wristband — communicate to ALL team members

Immunodeficiency Disorders

Immunodeficiency is a state in which the immune system is unable to mount an adequate response, leaving the individual highly vulnerable to infections that would not normally cause serious disease in healthy individuals — called 'opportunistic infections.' Immunodeficiency is classified as primary (congenital/inherited) or secondary (acquired). PRIMARY IMMUNODEFICIENCY — Genetic defects present from birth, usually manifesting in infancy or early childhood as recurrent, severe, unusual infections. KEY EXAMPLES: (1) Severe Combined Immunodeficiency (SCID) — the classic primary immunodeficiency; BOTH B cells and T cells are absent or nonfunctional; children are profoundly susceptible to all types of infection; historically called 'bubble boy disease' because affected children must live in a protective sterile environment; treated with bone marrow/stem cell transplant. (2) Bruton Agammaglobulinemia (X-linked) — affects only B cells; males primarily affected; no immunoglobulins produced; presents after 3–6 months (when maternal IgG wanes); treated with IVIG. (3) Selective IgA Deficiency — most common primary immunodeficiency; IgA is absent; recurrent respiratory and GI infections. (4) DiGeorge Syndrome — thymic aplasia/hypoplasia; T cell deficiency (humoral immunity relatively intact); associated with cardiac defects and hypocalcemia (parathyroid involvement); chromosome 22q11 deletion. SECONDARY IMMUNODEFICIENCY — Far more common than primary; results from another condition or treatment that impairs the immune system. CAUSES: (1) HIV/AIDS — the most important globally and in Philippine public health; HIV destroys CD4+ helper T cells; when CD4+ count falls below 200 cells/mm³, diagnosis of AIDS is made; cells critical for both humoral and cell-mediated immunity are lost, leading to opportunistic infections (Pneumocystis jirovecii pneumonia, tuberculosis, CMV retinitis, Cryptococcus meningitis, Toxoplasma encephalitis); (2) Malignancy — leukemia and lymphoma impair WBC function; (3) Chemotherapy and radiation — destroy rapidly dividing cells including bone marrow cells producing immune cells; (4) Immunosuppressive drugs — corticosteroids (used for transplant, autoimmune disease), cyclosporine, tacrolimus; (5) Malnutrition — protein-calorie malnutrition impairs all aspects of immunity; very relevant in Philippine context; (6) Splenectomy — removes the organ that filters blood-borne pathogens and produces antibodies; increased risk for encapsulated bacterial infections (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis); (7) Aging — immunosenescence (natural decline of immune function with age). NURSING MANAGEMENT OF IMMUNODEFICIENCY: (1) PROTECTIVE (NEUTROPENIC) PRECAUTIONS — private room (positive pressure for SCID/severely neutropenic); meticulous hand hygiene (most important measure!); limit visitors; no fresh flowers, standing water, or raw fruits/vegetables for severely neutropenic patients (sources of environmental pathogens); no live vaccines; (2) INFECTION SURVEILLANCE — fever may be the ONLY sign of infection in immunosuppressed patients (no inflammatory response means no classic signs); report any temperature elevation ≥38°C promptly; (3) IVIG REPLACEMENT THERAPY — for antibody deficiency disorders; infuse SLOWLY (to prevent anaphylactoid reactions); premedicate with antihistamine and acetaminophen; monitor for fever, chills, hypotension during infusion; (4) NUTRITIONAL SUPPORT — adequate protein and calorie intake supports immune function; (5) PATIENT AND FAMILY EDUCATION — hand hygiene, infection prevention, when to seek care, medication adherence (especially for HIV patients on antiretroviral therapy, ART).

Examples

PCP prophylaxis with TMP-SMX is initiated when CD4+ falls below 200 cells/mm³. This is part of Philippine DOH HIV/AIDS treatment guidelines. The nurse must recognize opportunistic infection patterns based on CD4+ levels.

Scenario

A 24-year-old male patient in a Philippine DOH HIV treatment hub has a CD4+ count of 180 cells/mm³ and is not yet on antiretroviral therapy (ART). He develops a dry cough, fever, and progressive dyspnea.

Solution

This presentation in a patient with CD4+ < 200 cells/mm³ is highly suspicious for Pneumocystis jirovecii Pneumonia (PCP) — the most common opportunistic infection in AIDS. Priority nursing actions: assess respiratory status (SpO2, RR, breath sounds), position for comfort (semi-Fowler's), administer O2 as ordered, prepare to collect sputum specimen for diagnosis, administer trimethoprim-sulfamethoxazole (TMP-SMX) as ordered, educate patient on ART initiation.

Live vaccines contraindicated in immunodeficiency: OPV, MMR, BCG, varicella, yellow fever, rotavirus. Inactivated/killed vaccines and toxoids (IPV, hepatitis B, tetanus toxoid) are generally safe but may not generate adequate response. This is a critical Philippine EPI-related NLE consideration.

Scenario

A 4-year-old child with SCID is admitted to a Philippine children's hospital. The parents ask why their child cannot be given the oral polio vaccine (OPV) that was administered in the barangay health center.

Solution

OPV is a LIVE ATTENUATED vaccine. In SCID — where both B and T cells are absent — the attenuated (weakened) vaccine virus cannot be controlled by the immune system and can cause actual poliovirus infection (vaccine-associated paralytic poliomyelitis). Live vaccines are ABSOLUTELY CONTRAINDICATED in severe immunodeficiency.

Applications

  • HIV/AIDS nursing care in Philippine DOH treatment hubs — monitoring CD4+ counts, ART adherence, opportunistic infection prophylaxis
  • Neutropenic precautions for chemotherapy patients in Philippine oncology wards
  • Pre-splenectomy vaccination with pneumococcal, meningococcal, and Hib vaccines as per Philippine DOH protocols
  • IVIG administration nursing protocol in Philippine tertiary hospitals
  • Community health nursing: early detection of malnutrition-related immunodeficiency in barangay health centers

Misconceptions

  • Misconception: All immunocompromised patients will show classic signs of infection (fever, redness, pus). Fact: Neutropenic/immunosuppressed patients may have BLUNTED inflammatory responses — fever alone may be the only sign; absence of pus or redness does NOT rule out serious infection.
  • Misconception: BCG vaccine (given to all Filipino newborns) is safe for all immunocompromised patients. Fact: BCG is a live attenuated vaccine and is CONTRAINDICATED in immunodeficiency, including SCID and HIV with low CD4+ counts — can cause disseminated BCG disease.
  • Misconception: IVIG should be infused rapidly for faster therapeutic effect. Fact: IVIG must be infused SLOWLY — rapid infusion can cause anaphylactoid reactions (flushing, chills, hypotension) due to complement activation and cytokine release.
  • Misconception: Secondary immunodeficiency is less serious than primary. Fact: HIV/AIDS-associated secondary immunodeficiency kills more people worldwide than all primary immunodeficiencies combined.

Related Concepts

  • HIV/AIDS Nursing Care (NCM 103)
  • Neutropenic Precautions
  • Opportunistic Infections
  • IVIG Therapy
  • Philippine EPI and Vaccine Contraindications
  • Type I Hypersensitivity (SCID and IVIG reactions)

Common Exam Questions

Example

A male infant has recurrent serious bacterial infections beginning at 6 months of age, with absent serum immunoglobulins but normal T-cell function. This most likely represents: (Answer: Bruton agammaglobulinemia — X-linked, B-cell deficiency, presents at 6 months when maternal IgG wanes)

Approach

Distinguish primary from secondary immunodeficiency by age of onset and cause. Know the classic examples: SCID (primary, both B+T), DiGeorge (primary, T cell), HIV/AIDS (secondary).

Question Type

Identification/Classification

Example

A nurse is caring for a patient receiving chemotherapy with an ANC of 300 cells/mm³. Which intervention is MOST important? A) Administer IVIG B) Encourage frequent hand hygiene by patient and all visitors C) Give pneumococcal vaccine D) Apply oxygen via nasal cannula (Answer: B — hand hygiene is the single most effective infection prevention measure)

Approach

In immunocompromised patients, the priority is always INFECTION PREVENTION. The most important single measure is HAND HYGIENE. Always choose interventions that minimize infection risk.

Question Type

Nursing intervention priority

Key Points To Remember

  • SCID = both B cells AND T cells absent = classic primary immunodeficiency = 'bubble boy disease'
  • DiGeorge syndrome = T-cell deficiency (thymus aplasia) + cardiac defects + hypocalcemia
  • HIV/AIDS = classic secondary immunodeficiency; CD4+ < 200 cells/mm³ = AIDS diagnosis
  • HIV destroys CD4+ helper T cells → impairs both humoral and cell-mediated immunity
  • Neutropenic/protective precautions: private room, meticulous hand hygiene, no raw produce, no flowers/standing water, no live vaccines
  • FEVER may be the ONLY sign of infection in immunocompromised patients — ALWAYS investigate and report promptly
  • LIVE vaccines are CONTRAINDICATED in significant immunodeficiency (risk of vaccine-strain infection)
  • Post-splenectomy patients are at high risk for encapsulated bacteria — vaccinate pre-splenectomy (pneumococcal, meningococcal, Hib)
  • IVIG: infuse slowly, premedicate to prevent infusion reactions, monitor vital signs throughout

Practice Problems

Using Maslow's hierarchy, airway is always the most basic physiological need — it is the top priority. Although hypotension is also present (suggesting shock), the stridor indicates laryngeal edema — the leading cause of death in anaphylaxis. Epinephrine simultaneously addresses both the airway (bronchodilation, reduces laryngeal edema) and the circulation (vasoconstriction → raises BP). Antihistamines and corticosteroids are adjuncts — never first-line. The NANDA nursing diagnosis 'Ineffective Airway Clearance' or 'Risk for Suffocation' is appropriate. RA 9173 mandates competent nursing response to emergencies.

Problem

A 35-year-old woman with a history of penicillin allergy is brought to the ER after receiving amoxicillin at a local clinic. She has generalized urticaria, audible stridor, BP of 75/40 mmHg, and RR of 28 breaths/min with bilateral wheezing. Using the nursing process, identify the PRIORITY nursing diagnosis and the FIRST nursing intervention.

Solution

PRIORITY NURSING DIAGNOSIS: Ineffective Airway Clearance related to laryngeal edema and bronchospasm as evidenced by stridor, wheezing, and dyspnea (Maslow Level 1 — Physiological Safety: Airway). FIRST NURSING INTERVENTION: Administer EPINEPHRINE 0.5 mg of 1:1000 solution IM into the anterolateral thigh IMMEDIATELY, while simultaneously calling for emergency assistance.

Live vaccines contraindicated in pregnancy: MMR, varicella, OPV, yellow fever, BCG. The rubella component of MMR is teratogenic (causes birth defects: cataracts, deafness, cardiac defects) when contracted during early pregnancy. Postpartum vaccination is safe and is part of Philippine DOH maternal immunization protocol. This tests the nurse's understanding of the distinction between active immunity types and vaccine safety.

Problem

A nurse in a Philippine community health center is counseling a 28-year-old pregnant woman, 8 weeks gestation, who has never had rubella. She asks: 'Should I get the rubella vaccine now to protect my baby?' What is the nurse's correct response and rationale?

Solution

The nurse should advise AGAINST giving the MMR (rubella) vaccine during pregnancy. The rubella vaccine is a LIVE ATTENUATED vaccine — it is contraindicated in pregnancy because the live attenuated virus can potentially cross the placenta and cause congenital rubella syndrome in the fetus. The nurse should: (1) Advise the mother that vaccination should be given AFTER delivery (postpartum vaccination during hospitalization); (2) Advise avoiding contact with persons with rubella during pregnancy; (3) Explain that the baby will receive some passive immunity from maternal IgG if the mother is immune, but since she is not immune, both mother and newborn are at risk; (4) Schedule MMR vaccination immediately postpartum — ensure she does not become pregnant within 4 weeks after vaccination.

Mantoux interpretation cutoffs: ≥5 mm = positive for immunocompromised (HIV, transplant, close contact with active TB, abnormal chest X-ray); ≥10 mm = positive for healthcare workers, residents in congregate settings, immigrants from high-prevalence areas, BCG-vaccinated, children under 5; ≥15 mm = positive for any person with no risk factors. A positive Mantoux = TYPE IV hypersensitivity reaction = evidence of prior sensitization to M. tuberculosis — NOT diagnostic of active disease. Chest X-ray and sputum AFB are needed. This is a critical Philippine TB control program (NTP) nursing application.

Problem

Nurse Ben is reading the results of Mantoux (PPD) tests performed 48 hours ago on three healthcare workers. Worker A: 8 mm induration; Worker B: 12 mm induration (previously BCG vaccinated); Worker C: 6 mm induration with HIV-positive status and CD4+ count of 150 cells/mm³. Which workers have a POSITIVE Mantoux result? Explain the basis.

Solution

Worker A (8 mm): Typically NEGATIVE — standard cutoff for most healthcare workers is ≥10 mm. Worker B (12 mm): POSITIVE — ≥10 mm is the cutoff for healthcare workers and BCG-vaccinated individuals; a positive result still requires follow-up chest X-ray to rule out active TB. Worker C (6 mm): POSITIVE — for immunocompromised patients (HIV, organ transplant, immunosuppressive therapy), the cutoff is ≥5 mm because their blunted immune response means even a small induration is clinically significant.

Spina bifida = highest risk group for latex allergy (40–65% prevalence). Balloon rash = classic history of latex sensitization. Avocado reaction = latex-food cross-reactivity (ABCK: Avocado, Banana, Chestnut, Kiwi). The avocado reaction with throat swelling suggests possible Type I IgE-mediated sensitization — at risk for intraoperative anaphylaxis. The first-case-of-the-day scheduling is a specific, high-yield NLE nursing intervention for latex allergy. Missing latex allergy identification can result in fatal intraoperative anaphylaxis.

Problem

A 6-year-old child with spina bifida is scheduled for a ventriculoperitoneal shunt revision. During preoperative assessment, the child's mother mentions that the child always develops a rash when playing with balloons and had throat swelling once when eating avocado. What actions should the nurse take?

Solution

(1) IMMEDIATELY flag this patient as HIGH RISK FOR LATEX ALLERGY — both the spina bifida diagnosis AND the history of balloon rash and avocado reaction are red flags (latex-food cross-reactivity with avocado). (2) Notify the surgical team and anesthesiologist. (3) ORDER A LATEX-FREE ENVIRONMENT — non-latex gloves, latex-free IV tubing, non-latex catheter, non-latex blood pressure cuff, etc. (4) SCHEDULE THE PATIENT AS THE FIRST CASE OF THE DAY to minimize aerosolized latex in the OR. (5) Label the patient's chart, wristband, and room door with 'LATEX ALLERGY' in red. (6) Prepare emergency anaphylaxis equipment at the bedside and in the OR. (7) Educate the mother to inform ALL future healthcare providers and to avoid latex products at home.

Using ACID: Anaphylactic (I), Cytotoxic (II), Immune complex (III), Delayed (IV). The key distinguishing features: timing (minutes = I; 24–72 hours = IV; variable = II and III), mediator (IgE = I; IgG/IgM against cell surface = II; immune complexes = III; T cells, NO antibody = IV), and clinical presentation. These four types appear in almost every NLE immunology section.

Problem

Match each clinical scenario to the correct hypersensitivity type (I, II, III, or IV) and name the mediator responsible: (A) A patient develops a butterfly facial rash, arthralgias, and proteinuria 3 weeks after a streptococcal throat infection; (B) A nurse develops itchy, oozing skin lesions on the hands 36 hours after switching to a new brand of latex gloves; (C) A patient receiving a blood transfusion develops acute flank pain, dark urine, and fever 15 minutes into the transfusion; (D) A patient with bee sting allergy develops urticaria and bronchospasm within 2 minutes of being stung.

Solution

(A) Type III — Immune Complex Hypersensitivity. Antigen (streptococcal proteins) + IgG/IgM → immune complexes → deposit in kidneys (glomerulonephritis), joints, skin → complement activation → inflammation. (B) Type IV — Delayed (Cell-Mediated) Hypersensitivity. T lymphocyte-mediated contact dermatitis to rubber chemical additives in gloves; onset 24–48 hours; no antibody involved. (C) Type II — Cytotoxic Hypersensitivity. IgM antibodies against donor ABO antigens → complement-mediated intravascular hemolysis → hemoglobinuria (dark urine), flank pain (renal), fever. (D) Type I — Anaphylactic (Immediate) Hypersensitivity. IgE on mast cells + bee venom antigen → mast cell degranulation → histamine + leukotrienes → urticaria + bronchospasm within minutes.

Exam Preparation Tips

  • Master the ACID mnemonic for hypersensitivity types: I=Anaphylactic, II=Cytotoxic, III=Immune complex, IV=Delayed — then match clinical scenarios to these types using onset timing and mediator as clues
  • EPINEPHRINE is the answer to ALL anaphylaxis priority action questions — do not be distracted by answer choices listing antihistamines or corticosteroids first; these are adjuncts only
  • Always know your concentrations: Epinephrine 1:1000 (1 mg/mL) = IM for anaphylaxis; Epinephrine 1:10,000 (0.1 mg/mL) = IV for cardiac arrest — NLE has tested this distinction directly
  • Memorize immunoglobulin functions using key phrases: 'IgG Goes across the placenta,' 'IgM = iMMediate first response in acute infection,' 'IgA = secretory (saliva, tears, breast milk),' 'IgE = Emergency allergy antibody'
  • For active vs. passive immunity questions: ask yourself — did the person MAKE antibodies (active) or RECEIVE them (passive)? Active = slow but lasting; Passive = immediate but temporary
  • For the Mantoux test: know the three cutoffs (≥5 mm immunocompromised, ≥10 mm healthcare workers/BCG-vaccinated, ≥15 mm everyone else) — a positive Mantoux is a Type IV reaction, NOT proof of active TB
  • Spina bifida = highest latex allergy risk — this specific fact appears regularly in NLE. Know the latex-food cross-reactivity list (Avocado, Banana, Chestnut, Kiwi = ABCK)
  • For immunodeficiency patients: fever is often the ONLY sign of infection — always investigate and report; and LIVE vaccines are CONTRAINDICATED — know which vaccines are live (MMR, OPV, BCG, varicella, rotavirus, yellow fever)
  • Use Maslow's hierarchy for prioritization: airway problems (anaphylaxis, laryngeal edema) always take priority over circulation problems (hypotension) — but epinephrine actually addresses both simultaneously
  • SCID = both B and T cells absent (primary immunodeficiency); HIV/AIDS = CD4+ destruction (secondary immunodeficiency) — these are the 'classic examples' the NLE uses for each category
  • Practice NANDA nursing diagnoses for immune disorders: 'Ineffective Airway Clearance,' 'Decreased Cardiac Output,' 'Risk for Infection,' 'Deficient Knowledge' — and apply them to anaphylaxis and immunodeficiency scenarios
  • In drug allergy questions: ALWAYS verify allergy history before administering penicillin (most classic drug anaphylaxis allergen) and radiocontrast agents — this is a nursing standard under RA 9173 Section 28 on competent nursing practice
  • Remember biphasic anaphylaxis — observe ALL anaphylaxis patients for minimum 4–8 hours after recovery; this prevents premature discharge questions in the NLE
  • For blood transfusion reaction (Type II hypersensitivity): the priority action is always to STOP the transfusion first, then maintain IV access with NORMAL SALINE (not the transfusion tubing), then notify the physician and blood bank
  • Review Philippine DOH programs: EPI vaccines (artificial active immunity), HIV treatment hubs (secondary immunodeficiency management), National TB Program (Mantoux interpretation) — NLE community health questions frequently integrate immunology with Philippine health programs
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In summary

Immunity, hypersensitivity, and allergic disorders represent one of the most clinically vital and NLE-heavy chapters in nursing education. The core framework to master is the distinction between innate (nonspecific, no memory) and adaptive (specific, with memory) immunity — and within adaptive immunity, the contrast between humoral (B cells, antibodies) and cell-mediated (T cells) arms. The five immunoglobulin classes each play a distinct, testable role: IgG crosses the placenta and drives memory responses; IgM is the first antibody in acute infection; IgA protects mucosal surfaces and is secreted in breast milk; IgE is the allergy antibody that triggers mast cell degranulation; and IgD serves as a B-cell surface receptor. The active-passive immunity distinction is fundamental for understanding vaccination strategy, post-exposure prophylaxis, and maternal-neonatal immunity — all of which are integrated into Philippine DOH programs that the NLE tests regularly. The four hypersensitivity types (ACID) must be memorized with their mediators, timing, and clinical examples — from anaphylaxis (Type I, IgE, minutes) to contact dermatitis and the Mantoux test reaction (Type IV, T cells, 24–72 hours). Anaphylaxis management is perhaps the single most important emergency skill in this chapter: EPINEPHRINE 0.3–0.5 mg IM (1:1000) in the anterolateral thigh is always the first-line, life-saving intervention — antihistamines and corticosteroids are adjuncts that can never replace it. The leading cause of death is laryngeal edema — not hypotension. Latex allergy demands proactive nursing assessment, especially in high-risk groups like spina bifida patients, with latex-free environments and first-case-of-the-day OR scheduling as key interventions. Immunodeficiency — whether primary (SCID) or secondary (HIV/AIDS) — requires protective precautions, avoidance of live vaccines, vigilance for subtle infection signs (fever may be the only sign!), and compassionate education. Under RA 9173, the Philippine Nursing Act of 2002, every registered nurse has the professional and legal obligation to practice with competence — and in immune emergencies, competent practice means recognizing anaphylaxis within seconds and responding with the correct drug, dose, route, and sequence. Master this chapter, and you master both the examination and the clinical practice it prepares you for.

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Immunity, Hypersensitivity and Allergic Disorders

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