Learning Objectives
1. Differentiate the following: allergy, antigen, immunogens, antibody, and histamine.
2. Demonstrate the procedure for intradermal skin testing.
3. Discuss three components of the medical history and the physical examination that relate to the detection of allergies.
4. State three possible skin and three possible respiratory manifestations of the allergic response.
5. Discuss five possible gastrointestinal manifestations of the allergic response.
6. Discuss three possible manifestations of the allergic response that relate to drugs.
7. State three methods for treating multisystem allergy response.
8. Discuss five nursing considerations related to prevention and treatment of anaphylaxis.
9. Compare and contrast organ-specific and nonorgan-specific autoimmune diseases.
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IMPORTANT TERMINOLOGY |
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allergen hives |
non-organ-specific |
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allergy induration |
organ-specific |
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anaphylaxis immunogen |
urticaria |
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autoimmune disorder immunosuppression |
wheals |
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eczema immunotherapy |
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histamine leukotrienes |
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Acronyms |
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AIDS |
IgE |
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HIV |
SLE |
The complex human immune system protects individuals against “foreign invaders” (antigens). This protection is called the immune response. Sometimes, however, the immune system works against a person’s best interests, and an allergy, immune, or autoimmune disorder results.
Allergy, a common problem, is defined as a hypersensitivity disorder of the immune system involving one or more substances such as is found in the environment, in medications, or in foods. The physician who treats allergies is called an allergist, although internal medicine and family practice specialists also treat clients with allergies. In addition, pediatricians see many children with allergies.
Normal immunity is based on the body’s ability to recognize foreign proteins and to marshal its defenses to destroy foreign matter. Immune mechanisms are not always positive or beneficial to the body. When an antigen (a foreign protein substance) touches or enters the body, the body reacts by producing antibodies, also known as immunoglobulins, for protection against that antigen. The antigen-antibody reaction releases chemical mediators, the most common being histamine. These mediators initiate a series of physiologic events in the body’s organs. Because antibodies form after initial contact with an antigen, an allergic reaction cannot occur at the first exposure to an antigen. Subsequent contact with the antigen may cause an allergic reaction with a wide variety of symptoms. One type of immune disorder is an autoimmune disorder. Normally, the body is able to distinguish “self’ from “not self’ and takes steps to eliminate substances in the “not self’ category. The difficulty in an autoimmune disorder is that the body fails to recognize its own cells as “self’ and begins to destroy them.
Key Concept Disorders of the immune system are believed to contribute to or cause many systemic symptoms and problems. For example, allergies are responsible for symptoms that range from rhinorrhea and skin rash to asthma or a total anaphylactic response.
DIAGNOSTIC TESTS
Determining the cause of an allergy, immune, or autoimmune disorder is often difficult. A person’s antigen-antibody response may vary with fatigue, seasons, or hormones. A detailed medical history and physical examination are needed to help establish a diagnosis (Box 84-1). To further establish a diagnosis, laboratory and skin tests are performed.
Laboratory Tests
Laboratory tests include a complete blood count with white blood cell differential and eosinophil count, an eosinophil smear of secretions, and measurement of blood levels of immune response factors such as IgE (immunoglobulin E).
BOX 84-1. Important Medical History and Physical Examination Information for Diagnosing Allergies and Immune Problems
Important medical history information includes information about the following:
♦ Onset, duration, nature, and progression of symptoms
♦ Factors that aggravate and alleviate symptoms
♦ Possible environmental or occupational exposures, such as smoking, hobbies, household activities, and animals
♦ History of family allergies
♦ Medication usage
Important physical examination information includes the following:
♦ Skin observation
♦ Color (e.g., erythema, cyanosis, pallor)
♦ Temperature
♦ Rashes
♦ Pruritus (itching)
♦ Hives ([urticaria] pink edematous elevations)
♦ Respiratory observation
♦ Nasal edema and congestion
♦ Sneezing
♦ Rhinorrhea
♦ Edema of the oropharynx
♦ Hoarseness
♦ Stridor
♦ Cough
♦ Dyspnea
♦ Wheezing
♦ Ear observation
♦ Tympanic membrane bulging or retraction
♦ Fluid levels
♦ Gastrointestinal tract observation
♦ Nausea, vomiting
♦ Altered peristalsis
♦ Cramping
♦ Diarrhea
♦ Cardiovascular observation
♦ Tachycardia
♦ Hypotension
♦ Syncope (fainting)
♦ Signs of shock
♦ Nervous system observation
♦ Anxiety
♦ Confusion
♦ Seizures
♦ Temperature elevation
♦ Behavioral changes
FIGURE 84-1 · Skin testing by intradermal injection. With the needle held nearly flat against the skin and the bevel up, the needle is inserted approximately one-eighth of an inch under the epidermis. The test agent is injected slowly as a small blister appears. Signs of positive reaction to the agent will appear in 24 to 48 hours.
Skin Tests
Skin tests are done to confirm suspected disorders or to determine the causes of allergic reactions. Several antigens are tested at one time, with each antigen injected intradermally (Fig. 84-1) or applied to a small scratch on the skin (epicuta-neous method). These areas are then labeled or otherwise identified. After 20 minutes, the provider reads the skin tests in much the same way as in a tuberculin test. Erythema (redness) and most commonly an induration (a lump, wheal, or edema) indicate a positive skin test. The degree of edema, measured in millimeters, indicates the severity of the reaction. In this way, the provider can identify which substances are causing the client’s reaction and to what extent the client reacts. Skin testing is not 100% accurate. A substance may or may not initiate an allergic reaction. A physician may order prescription or over-the-counter antihistamines, immunotherapy (allergy shots), or both for treatment of allergies.
Observe the client closely during a skin test because occasionally a test will cause a severe reaction. Such a reaction is unusual because the amount of the antigen used is very small; however, it may occur if the client is highly sensitive to it. Emergency airway management and epinephrine need to be available in case of severe or anaphylactic reactions.
NURSING PROCESS
DATA COLLECTION
Carefully observe and assess the client with an allergic or immune disorder. Perform a head-to-toe assessment to establish a baseline for future comparison. Question the client for symptoms, such as pruritus, shortness of breath, numbness, and tingling. Examine the client for signs such as a rash, urticaria, excessive tearing, rhinorrhea, sneezing, wheezing, or other respiratory signs, and localized edema or erythema. Document and report any abnormal findings or changes in this baseline level.
Report any allergies a client describes or exhibits. For the client’s protection, note any medication allergies in large letters on the front of the chart and on the medication record when the client is admitted. A client with allergies usually also wears a special identification band. Keep in mind that a person can have an allergic reaction to any medication. The reaction will occur faster and more dramatically if the medication is administered parenterally. Give no medication without first making sure that the client is not allergic to it. If there are any doubts, or if the client has a history of allergies or asthma, the physician may perform a skin (intradermal) test first. Even then, be prepared to deal with possible anaphylaxis.
The client with an immune disorder will generally present with vague symptoms such as fatigue or dyspnea, frequent or recurrent infections, slow wound healing, joint pain, skin rashes, or visual disturbances. Ask the client about any family history of cancer or immune disorders. The physician and other staff can further evaluate any reported abnormalities.
Observation of the immune system also includes the administration and evaluation of skin tests. The client’s medical history is particularly important in determining allergic and immune disorders. In addition, observe the client’s emotional response. Does the disorder interfere with the person’s daily life? What assistance does the client need?
NCLEX Alert When reading NCLEX questions be alert for clues suggesting an allergic disorder. Clinical scenarios may provide information that indicates potential or ongoing allergic reactions, especially anaphylaxis. Also, you must be able to prioritize appropriate medication administration during anaphylaxis (e.g., epinephrine, diphenhydramine, or corticosteroids).
PLANNING AND IMPLEMENTATION
Together, the client, nurse, and family plan for effective individualized care to meet the client’s needs. Provide supportive care and continuously monitor the client’s status. The client may require assistance with activities of daily living and in dealing with the emotional aspects of having a chronic disorder. Teach the client and family about the disorder, its prognosis, and treatment.
EVALUATION
Evaluate outcomes of care with the client, family, and other members of the healthcare team. Have the short-term goals been met? For example, are the client’s acute allergic symptoms controlled? Are long-term goals still realistic? Planning for further nursing care considers the client’s prognosis, as well as any complications and the client’s response to care given. For example, is the client complying with medications prescribed? The seriousness of the disorder influences the future planning for care and rehabilitation.
ALLERGIES
Antigens that cause an immune response in the body are known as immunogens. Sometimes, a tissue reaction may occur, in which case the antigens are called allergens. When a person has a tissue reaction to a specific substance, the person is called sensitive or allergic to the allergen. Allergens can enter the body in various ways, via:
• Inhalation: Pollen, dust, mold, grass, various plants, animal dander
• Ingestion: Medications (aspirin, penicillin), foods (chocolate, eggs, seafood, strawberries, nuts), preservatives
• Injection: Medications (e.g., antibiotics), insect stings or bites, immunization with animal serum, blood transfusions
• Direct contact: Poison ivy, cosmetics, dyes, metals, latex rubber, nylon, wool
Researchers believe the tendency toward allergic response is inherited, but this does not mean that specific allergies are inherited. The manifestation of allergy relates to many factors, including hormonal responses, type and concentration of allergen, body part involved, exposure to the allergen, and concurrent illness. Allergy symptoms can occur at any age and vary in response from mild to life threatening (as in anaphylaxis).
Allergic reactions can affect the skin and mucous membranes, the respiratory passages, and the gastrointestinal tract. They can result in rash, edema, itching, dyspnea, contractions of the smooth muscles, and, in severe cases, total shock and death (as may occur in anaphylaxis).
Edema may occur in one part of the body, such as the lips and eyelids, or it may be generalized. If the swelling presses on a vital organ, such as the larynx, it can severely impair the person’s ability to function.
Allergies With a Skin Response
Urticaria (Hives)
Reddened areas (erythema), itching (pruritus), and burning around swollen patches on the skin may appear. The swellings are called hives, wheals, or urticaria. They appear suddenly and may disappear after a few hours or may last for days or weeks. Hives may result from a variety of causes, including foods; additives; medications; viral, bacterial, or parasitic infections; or stress factors (e.g., heat, sun, cold, emotional stress). Management includes identification of the causative factor and the administration of medications, such as antihistamines, epinephrine, or steroids.
Eczema
In eczema (atopic dermatitis), tiny blisters that itch and ooze cover the skin, usually in the folds of the neck, elbows, and knees. In chronic eczema, the skin becomes scaly and thickened.
Contact Dermatitis
Contact dermatitis can result from contact with plant oils (e.g., poison ivy, poison oak, poison sumac), soaps, detergents, perfumes, cosmetics, metals in jewelry, leathers, wool, and latex products. Contact with the skin results in itching, swelling, redness, and blisters. In Practice: Nursing Care Plan 84-1 describes the care for a client with contact dermatitis.
