DRUG ALLERGY

(Drug Hypersensitivity)

 Basic information

description

Drug allergy is an allergic reaction caused by drugs. The reaction may happen immediately after using the drug or days to weeks later. Drug allergies can occur in any age group. Females are affected more often than males.

FREQUENT SIGNS & SYMPTOMS

• Rash (most common), hives (urticaria), itching skin.
• Wheezing.
• Swelling (lips, tongue, and/or face).
• Anaphylaxis (a life-threatening reaction). It can cause difficult breathing with a wheeze, hives, swelling, fainting, lightheadedness, dizziness, confusion, rapid pulse, fast heart rate, diarrhea, nausea or vomiting, and stomach pain or cramping.
• Serum sickness (a delayed type of reaction that occurs 1 to 3 weeks or more after exposure). It can occur with the first time use of a drug. Symptoms include fever, rash, joint pain, and nerve damage.

causes

A reaction of the immune system in certain people. It leads to a misdirected response against a substance that does not cause a response in most people. The body becomes sensitized by the first exposure to the drug. The second or subsequent exposure causes an immune response (production of antibodies and release of histamine). Injected drugs are more of a risk than those taken by mouth or applied to the skin.

risk increases with

• Use of almost any drug. The following are more likely:
  • Penicillin and cephalosporin antibiotics.
  • Sulfa drugs.
  • Vaccines.
  • Anesthetics applied to the skin.
  • Allergy extracts.
  • Iodine-containing compounds (used in some x-rays).
• Injected drugs, especially in high doses.
• Personal or family history of other allergies, such as hay fever, asthma, or eczema.
• Serious illness.
• Weak immune system due to illness or drugs.

PREVENTIVE MEASURES

• Tell any health care provider you consult about the drug reactions you have had.
• Learn the name of any drug you are given. If it causes a reaction, avoid it in the future.

expected outcomes

In many cases, stopping the drug is all that is needed. In other cases, symptoms can be relieved with treatment. Most symptoms should resolve in about 2 weeks.

possible complications

• Asthma.
• Hepatitis or kidney damage.
• Anaphylaxis (can be life-threatening if not treated).

 diagnosis & treatment

general measures

• Your health care provider may do a physical exam. Questions will be asked about your symptoms and the drugs you take (including nonprescription, herbals, or other supplements). Usually, a diagnosis can be made based on the type of reaction, the timing of the reaction, and that a drug you used is known to cause reactions. Sometimes, skin tests or blood tests are done.
• The first step of treatment is to stop using the drug that caused a reaction. Usually, another drug can be safely substituted. Symptoms of the drug reaction may be treated with other drugs.
• If there is no substitute drug that can be used, other treatment steps may be taken. There are methods (called desensitizing) that gradually introduce a drug into the body in small doses.
• Wear a medical alert type pendant or bracelet if you have drug allergy.
• 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.

medications

• Cortisone drugs to decrease inflammation, antihistamines for itching symptoms, and bronchodilators for wheezing may be prescribed.
• Epinephrine may be injected to treat anaphylaxis.

activity

No limits once symptoms improve.

diet

No special diet.

 notify our office if

• You have symptoms of drug allergy or observe them in someone else.
• You or a family member has anaphylaxis symptoms. This is an emergency! Call 911. Get help immediately!

Special Notes: