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



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

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

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