CH 38 STUDY GUIDE allergic disorders

Discuss the different allergic disorders according to type.

ATOPIC DERMATITIS RHINITIS LATEX

different immunoglobulin functions

*IgE= involved with an allergic reaction, two or more IgE molecules binding together to an allergen and triggering mast cells or basophils to release chemical mediators. RAST is a radioimmunoassay that measures allergen-specific IgE. The RAST indicates the quantity of allergen necessary to evoke an allergic reaction. *IgA=combines with antigens and activates complement, IgA protects against respiratory, gastrointestinal, and genitourinary infections. *IgB=coats the surface of B lymphocytes *IgG= is the principal immunoglobulin formed in response to most infectious agents, IgG also activates the complement system. *IgM=appears as the first immunoglobulin produced in response to bacterial and viral infections and also activates the complement system.

medication affinities

AFFINITY OF H1= antihistamines Diphenhydramine (Benadryl), biggest side effect is sedation AFFINITY OF H2= Cimetidine (Tagamet) and ranitidine (Zantac) target H2 receptors to inhibit gastric secretions in peptic ulcer disease.

RHINITIS ALLERGY

Allergic rhinitis is induced by airborne pollens or molds, occurring typically in early spring (tree pollen), early summer (rose and grass pollen), and early fall (weed pollen). Antihistamines are the major class of medications prescribed for the symptomatic relief of allergic rhinitis. The major side effect is sedation, although H1 antagonists are less sedating than earlier antihistamines. Allegra can be prescribed. Sudafed and Afrin are over-the-counter

what is an allergic disorder

An allergic disorder is characterized by a hyperimmune response to weak antigens that usually are harmless. The antigens that can cause an allergic response are called allergens.

atopic allergies are categorized by

Atopic allergic disorders are characterized by a hereditary predisposition and production of a local reaction to IgE antibodies produced in response to common environmental allergens

Atopic dematitis

use a topical skin moisturizer daily to help keep the skin hydrated. Likewise, the client should be encouraged to bathe daily. To minimize irritation, the client should wear only cotton fabrics. The client should maintain a room temperature between 68° F (20° C) and 72° F (22.2° C).

eosinphils and allergic disorders

Eosinophils, which are granular leukocytes, normally make up 0% to 3% of the total number of WBCs *A level between 5% and 15% is nonspecific but does suggest allergic reaction. *Higher percentages of eosinophils are considered to represent moderate to severe eosinophilia. *Moderate eosinophilia is defined as 15% to 40% eosinophils and may be found in patients with allergic disorders.

the most common med that is cause of anaphylaxis

Penicillin. Although aspirin, morphine (an opioid) and radiocontrast agents such as iodine can cause anaphylaxis, penicillin is the most comon cause of anaphylaxis, accounting for about 75% of fatal anaphylactic reactions in the United States each year.

LATEX ALLERGY

Routes of exposure to latex products can be cutaneous, percutaneous, mucosal, parenteral, or aerosol. most common is cutaneous. The best treatment available for latex allergy is the avoidance of latex-based products, but this is often difficult because of their widespread use. Antihistamines and an emergency kit containing epinephrine should be provided to these patients, along with instructions about emergency management of latex allergy. avoid using oil-based hand lotions before donning gloves because these lotions may leak latex proteins from the gloves, increasing skin exposure and the risk of developing true allergic reactions. Appropriate actions would include changing the brand of gloves used, using powder-free gloves, and applying water- or silicone-based moisturizing creams, lotions, or topical barrier agents

Describe measures to prevent and manage anaphylaxis.

Strict avoidance of potential allergens is an important preventive measure for the patient at risk for anaphylaxis. People who have experienced food, medication, idiopathic, or exercise-induced anaphylactic reactions should always carry an emergency kit containing epinephrine for injection to prevent the onset of the reaction upon exposure. Desensitization is based on controlled anaphylaxis, with a gradual release of mediators. Patients who undergo desensitization are cautioned that there should be no lapses in therapy, because this may lead to the reappearance of the allergic reaction when the use of the medication is resumed. The medical alert bracelet will assist those rendering aid to the patient who has experienced an anaphylactic reaction.

the test to measure how at risk a patient is for anaphylaxis is

The diagnosis of anaphylaxis risk is determined by prick and intradermal skin testing. Skin testing of patients who have clinical symptoms consistent with a type I, IgE-mediated reaction is recommended

how to manage a patient who has had an anaphylactic reaction

Watch the patient 4-10 hrs after they have received epinephrine as they may experience "Rebound reactions", which can occur from 4 to 10 hours after an initial allergic reaction.

less severe hypersensitivity responses include:

can include watery eyes, increased nasal and bronchial secretions, sneezing, vomiting, and diarrhea. Additional symptoms include hives (called urticaria), itching, and localized redness (e.g., in the conjunctiva of the eyes). Dark areas under the eyes, referred to as "allergic shiners," which are due to accumulation of blood around the orbit of the eye, may also be apparent.

Mild systemic reactions to food, shellfish etc consist of

peripheral tingling and a sensation of warmth, possibly accompanied by a sensation of fullness in the mouth and throat. Nasal congestion, periorbital swelling, pruritus, sneezing, and tearing of the eyes can also be expected.

Type 1-4 hypersensitivity

type 1= atopic, anaphylactic hypersensitivity is an immediate reaction, beginning within minutes of exposure to an antigen TYPE 2= cytotoxic, hypersensitivity occurs when the system mistakenly identifies a normal constituent of the body as foreign. involves binding either the IgG or IgM antibody to a cell-bound antigen, may lead to eventual cell and tissue damage. The reaction is the result of mistaken identity when the system identifies a normal constituent of the body as foreign and activates the complement cascade. Examples of type II reactions are myasthenia gravis, Goodpasture syndrome, pernicious anemia, hemolytic disease of the newborn, transfusion reaction, and thrombocytopenia. TYPE 3= systemic lupus erythematosus, rheumatoid arthritis, serum sickness, certain types of nephritis, and some types of bacterial endocarditis, it involves immune complexes formed when antigens bind to antibodies. TYPE 4=delayed-type, hypersensitivity occurs 24 to 72 hours after exposure to an allergen