DRUG HYPERSENSITIVITY

General Information

DEFINITION--A variety of allergic responses caused by medication. The reaction may be immediate--especially with a drug given intravenously--or the reaction may take a week to develop.

BODY PARTS INVOLVED--Skin; blood vessels; lungs.

SEX OR AGE MOST AFFECTED--Both sexes; all ages.

SIGNS & SYMPTOMS

Rash, itching or hives. Flushed skin. Anxiety. Serum sickness (fever, rash, joint pain and nerve damage). Anaphylaxis (wheezing and breathing difficulty). For signs and symptoms, see Anaphylaxis (in Illness section). Various blood disorders, such as hemolytic anemia. Peripheral neuropathy (nerve damage). Vasculitis (blood vessel inflammation). The following reactions to medications are usually not the result of allergy:

Vomiting or diarrhea. Fever. Photosensitivity (a skin reaction to sunlight).

CAUSES--Medications are "foreign" materials. When injected--or less often, when taken orally--the body develops antibodies to the medication. Subsequent exposure to the medication causes an allergic reaction in the body.

RISK INCREASES WITH

> Use of almost any drugs, but especially the following:

Penicillin and cephalosporin antibiotics. Sulfa drugs. Animal serums. Vaccines. Local anesthetics. Allergy extracts. Iodine-containing compounds, such as those used in some X-rays.

• Injected medications, especially in high doses.
• Medical history of other allergies, such as hay fever, asthma or eczema.
• Current infectious illness (probably because infection increases immune-system functions).

> Don't take medication--including non-prescription drugs--unless necessary.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and physical exam by a doctor.

APPROPRIATE HEALTH CARE

• Self-care.
• Doctor's treatment.
• Discontinuing of the the offending drug. Often another drug can be substituted.

POSSIBLE COMPLICATIONS

• Death from severe anaphylaxis reactions.
• Disability for many months from serum sickness.

PROBABLE OUTCOME--Most reactions disappear once the medication is permanently discontinued.

How To Treat

GENERAL MEASURES--

• Wear a Medic-Alert pendant or bracelet (See Glossary) if you have drug hypersensitivity. Even with a slight reaction the first time, subsequent exposure to the drug may initiate more severe reaction.
• Keep an anaphylaxis kit at home, on your person, nearby at work and in your car for emergency use if anyone in the family has had a severe drug reaction. Ask your doctor how to obtain one.

MEDICATION--Your doctor may prescribe:

• Cortisone drugs to decrease the inflammatory reaction.
• Antihistamines to decrease the body's allergic response.

ACTIVITY--Resume your normal activities as soon as symptoms improve.

DIET--No special diet.

Call Your Doctor If

You have symptoms of drug hypersensitivity or observe them in someone else.