Drug Allergy Clinic

Iowa’s only multidisciplinary drug allergy clinic

For Allergy and Immunology related requests:

For all other requests:: 1-800-777-8442

What is a drug allergy?

There are medications that can cause an allergic reaction. A drug allergy can be just a rash or hives on the skin. However, a more severe drug allergy is an allergic reaction often characterized by itching, hives, swelling of the throat, difficulty breathing, severe stomach/intestinal symptoms, and/or passing out. This group of symptoms is also known as anaphylaxis. Additionally, there are non-allergic side effects of drugs.

Research has shown that patients are labeled with a drug allergies when they may not actually have the allergy. Confirmation of a drug allergy is important because drug allergies may result in the use of less appropriate or more expensive drugs with more side effects. Even with a severe drug allergy, after 10 years it is known that 80% of people will no longer be allergic.

What is done during an evaluation for drug allergy?

A drug allergy evaluation is a way to test you to see if you have an allergy to a specific medicine. We care for our patients by using a team of medical providers, and you will see an allergy specialist with or without a pharmacist who will work together to discuss the diagnosis and create a care plan. The visit will typically take anywhere between two and three hours.

During the visit your provider will ask you questions about your drug allergy including the symptoms you had, how long ago it happened, when the reaction started and what you did for the symptoms. Following this history your provider may suggest evaluation with skin testing or a drug challenge.

If your allergy was more than 5 years ago and was not severe, you will most likely be offered a drug challenge alone. You will be given a full dose of the medicine on your allergy list and be observed for 60 minutes.

If your reaction was recent or severe, then generally you will have skin testing. This is done on your forearm with salt water (negative control), histamine (positive control), and the medication in question. This is typically a three-step process. The first step involves a scratch test on the skin. The second test is done under the skin (intradermal) with a needle. The third step is only done if skin testing is negative, and is a challenge to the medication in question, whenever possible. This testing takes approximately 90 minutes.