Testing for a Drug Allergy

Reviewed by Carol DerSarkissian on May 13, 2019

Most times, your doctor can diagnose a drug allergy based on your symptoms. Sometimes, though, drug allergies are harder to pin down. In these cases, they may suggest allergy testing.

There are a few different types:

Skin test: A doctor injects a tiny amount of the drug under your skin and watches to see if you have a reaction. Skin tests only work for some types of drugs, like penicillin and other antibiotics, muscle relaxants, and some cancer drugs.

Patch test: A doctor puts a small amount of a drug on your skin. After 2 to 4 days, the doctor will check for a reaction. This test can check for delayed allergic reactions to antibiotics, anticonvulsants, and other drugs.

Blood test: Lab tests may help diagnose some allergies to antibiotics and other drugs.

Talk with your doctor to see which is best for you.

WebMD Medical Reference

Sources

SOURCES:

Solensky, R. Annals of Allergy, Asthma & Immunology, October 2010.

UpToDate: "An approach to the patient with drug allergy."

© 2019 WebMD, LLC. All rights reserved.