Hypersensitivity

Innate

Present at birth, primary role is to defend pathogens, responds within minutes

Acquired

Development of immunity either actively or passively

Natural Active

Contact with antigen through infection (i.e.,varicella)

Artificial Acquired

Immunization with antigen (vaccine)

Natural Passive

Transplacental and colostrum from another to child (mother to baby)

Acquired Passive

Injection with antibodies (Injection of Hep B Immune globulin)

IgG

Only one that crosses the placenta

Second immune response

IgA

Lines mucous membranes

Protects body surfaces

IgM

Primary immune response

Forms antibodies to ABO blood antigens

IgD

Presents on lymphocyte surface aids in differentiation of B lymphocytes

IgE

Causes symptoms of allergic reactions

Fixes to mast cells and basophils

Aids in defense against parasitic infections

Greater susceptibility to infection

Older adults - Pneumonia and UTI

Type 1 - IgE Mediated

IgE antibodies made in response to allergen

Immediate

Pollen, drugs, food, dust

Anaphylaxis

Type 1 reaction

Can cause bronchial constriction, airway obstruction, vascular collapse

Anaphylaxis S/S

Edema, itching

Shock - rapid weak pulse, hypotension, dilated pupils, dyspnea, cyanosis

Bronchial and angioedema can compound shock

Anaphylaxis Causes

Drugs - antibiotics, ASA chemo, NSAIDs

Food - Eggs, milk, nuts, shellfish, peanuts

Insect bites - bees, wasps

Asthma treatments - blood products, iv contrast dye

Atopic - Allergic Rhinitis

Most common type 1 reaction

Hay fever

Year round or seasonal

Atopic - Allergic Rhinitis Causes

Dust, Mold, Pollens

Perennial (Year round) - dust mold animal clusters

Seasonal - Pollens, weeds, grasses

Atopic - Allergic Rhinitis S/S

Nasal Drainage, Sneezing, Tearing

Mucosal swelling in airway obstruction

itching around eyes, nose, throat, mouth

Asthma

Type 1 reaction

Atopic disorders (eczema, allergic rhinitis and food intolerances).

Produce smooth muscle constriction - dyspnea, wheezing

Excess thick mucus

Edema of the mucous membranes and bronchi

Decreased lung compliance.

Atopic Dermatitis

Type 1 Reaction

Chronic, inherited skin disorder

Environmental allergens

Skin lesions are generalized and involve vasodilation of blood vessels resulting in interstitial edema with vesicle formation.

Urticaria

Hives

Cutaneous skin reaction against allergens

Transient wheals (pink, raised, edematous, pruritis areas) that vary in size and shape

Histamine causes localized vasodilation (erythema), transudation of fluid (wheal), and flaring.

Angioedema

Principal areas of involvement include eyelids, lips, tongue, larynx, hands, feet, GI tract, and genitalia

Swelling usually begins in face and then progresses to the airway and other parts of the body.

Type 2 - Cytotoxic and Cytolytic Reactions

Direct binding of IgG or IgM antibodies to an antigen on the cell surface

Minutes to hours

Cell Surface of RBC’s

Cell basement membrane

Hemolytic Transfusion Reaction - S/S

Fever, chills, flank pain, hematuria.

Acute kidney injury can occur from hemoglobinuria

Hemolytic Transfusion Reaction

Type 2 reaction

When recipient receives ABO-incompatible blood from a donor

If transfused with incompatible blood, antibodies immediately coat the foreign erythrocytes, causing agglutination (clumping)à blocks blood vessels

Good Pasture Syndrome

Type 2 reaction

Disorder involving the lungs and kidneys

Deposits of IgG form along the cell basement membranes of the lungs and kidneys

The reaction results in pulmonary hemorrhage and glomerulonephritis.

Type 3 - Immune Complex Reactions

Soluble antigens combine with IgG and IgM to form complexes too small to be effective removed and complexes deposit into the tissue or small blood vessels

Hours to days

Extracelluar fungal, viral, bacterial

Type 3 - Immune Complex Reactions Manifestations

May be local of systemic and immediate or delayed

Manifestations depend on the number of complexes and the location in the body

Common sites for deposit are kidneys, skin, joints, blood vessels, and lungs.

Severe reactions are associated with autoimmune disorders such as Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Acute Glomerulonephritis.

Type 4 - Delayed Hypersensitive Reactions

Cell mediated response. Although cell mediated responses are usually protective, tissue damage occurs in delayed hypersensitivity reactions.

Several days

Intracellular or Extracellular

Contact Dermatitis

Type 4 reaction

Skin is exposed to substances that easily penetrate the skin to combine with epidural proteins

Appears erythematous and are covered with papules, vesicles, and bullae.

The area involved is often pruritic.

Contact Dermatitis Causes

Most common substances are metal compounds (nickel, mercury), rubber compounds, poison ivy, poison oak, and poison sumac, cosmetics and some dyes

Microbial Hypersensitivity Reactions

Type 4 reaction

A classic example is the body’s defense against

tubercle bacilli.

Basis for PPD test.

Transplant Rejection

Type 4 reaction

The body rejects foreign organ transplanted into the body.

Symptoms: fever, chills, body aches, N/V, pain at transplant site.

Allergic Disorders Assessment

Complete H & P.

Information about family allergies, social and environmental factors, and complete history of known allergies.

Allergic Disorders Family History

Family history-atopic reactions.

Past and present allergies.

Manifestations of any allergic reactions.

Social and environmental factors, physical environment is important.

Ask about animals, trees, plants, pollutants, floor coverings, heating and cooling systems in home and workplace, food diary.

Allergic Disorders S/S

Itchy, watery eyes, nasal drainage, swollen lips or tongue, itching, hives, wheezing.

Allergic Disorders - Diagnostic Testing

CBC with diff

immunoglobulins can indicate response (i.e., IgE high with Type I reactions).

Skin tests-scratch, intradermal or patch.

Scratch/intradermal 5-10 minutes, patch worn 48-72 hours.

Watch for anaphylaxis.

Anaphylaxis Management

Airway, IV access, Epi, Nebulizer

Antihistamines and Corticosteroids.

Chronic Allergies Management

Allergen control, asthma and hives may worsen with emotional stress,

environmental-cleaning and avoiding allergens

drugs - avoid and wear allergy bracelets

foods - avoid and carry Epi-pen and insect stings- carry EpiPen.

Drug Therapy - Antihistamines

Allergic rhinitis, itching, hives

1st generation Diphenhydramine →drowsiness

2nd generation Zyrtec, Allegra

Claritin → fewer side effects.

Drug Therapy - Sympathomimetics

Epinephrine for anaphylaxis

Allergic rhinitis →Phenylephrine and Pseudoephedrine [decongestants].

Corticosteroids-nasal spray-allergic rhinitis, IV or course of steroids may be needed.

Drug Therapy - Antipruritic agents

calamine, camphor, coal tar solutions.

Drug Therapy - Mast cell stabilizing drugs

Cromolyn-allergic rhinitis, inhibits release of histamine, nasal or nebulizer.

Drug Therapy - Leukotriene receptors antagonist

allergic rhinitis and asthma

Drug - Immunotherapy

Treatment when allergen cannot be avoided, and drug therapy is not effective.

SQ injection or SL.

Small amounts and the increasing for until hyposensitivity is achieved.

Should have emergency airway equipment and watch for anaphylaxis.

Latex Allergies - Type 1

Response to natural rubber proteins.

Redness, hives, rhinitis, conjunctivitis, or asthma to full blown anaphylaxis.

Latex Allergies - Type 2

Delayed response starts as dryness, itching and fissuring of the skin, followed by redness, swelling and crusting

Latex-food syndrome

Some proteins in rubber and similar to food proteins

Some foods may cause allergy in patients with latex allergies such as

bananas, avocado, chestnut, kiwi

tomato, water chestnut, guava,

hazelnut, potato, grape, and apricot

Latex Allergies Management

Medical alert bracelet and carry an epi-pen.

Latex precautions, latex free carts.