Drug allergies are a group of symptoms caused by a reaction to a medication. The first time taking medicine may not cause problems. But the body's immune system may produce an antibody against that drug. The next time the drug is taken, the antibody may cause white blood cells to make histamines. Histamines and other chemicals cause your allergy symptoms.
Common drugs that may cause allergies include seizure drugs, insulin (especially animal sourced), substances containing iodine, such as x-ray contrast dyes, penicillin-related antibiotics, and sulfa drugs.
Common symptoms of a drug allergy include hives; itching of the skin or eyes (common); skin rash (common); swelling of the lips, tongue, or face; and wheezing.
Symptoms of anaphylaxis — a more dangerous reaction — include abdominal pain or cramping; confusion; diarrhea; difficulty breathing with wheezing or hoarse voice; dizziness; fainting, lightheadedness; hives over different parts of the body; nausea, vomiting; rapid pulse; sensation of feeling the heart beat (palpitations).
Treatment for drug allergies may include antihistamines to relieve mild symptoms such as rash, hives, and itching; bronchodilators such as albuterol to reduce asthma-like symptoms; corticosteroids applied to the skin, given by mouth, or intravenously; epinephrine by injection to treat anaphylaxis.
Avoid all allergy-inducing medicines and similar drugs and make sure all your healthcare providers know about drug allergies that you or your children have.