Drug Allergies: What to Expect From a Doctor

Reviewed by Nayana Ambardekar, MD on June 13, 2020

Doctors are careful when diagnosing a drug allergy. Allergic reactions to drugs are different from more common drug side effects and can mimic some other conditions.

What will happen when you go to your doctor's office?

A physical exam: Your doctor will carefully check you -- especially your skin -- to see if you have a rash or hives.

Some questions: Your doctor will want details about the medicines you've been using, your symptoms, and your health.

Blood tests: If you’ve had a serious skin reaction, your doctor may ask for these to check how your organs are working and to see if there are any other signs of an allergic reaction.

Other tests: Depending on your case, your doctor may need to see some other things, like a chest X-ray.

Treatment: If your symptoms are severe, your doctor will give you medicine to help control the reaction.

Diagnosing and Managing a Drug Allergy

After the exam, your doctor may suggest:

Switching drugs: If your doctor thinks you are allergic to a drug, they will have you stop using that drug and may switch you to a different one.


Allergy testing: If there's any doubt if you are truly allergic, they may want you to have more tests. Keep in mind that the tests don’t work for all drugs.

Trying to reduce your reaction: If switching drugs isn't an option -- and you must keep taking a drug for your health -- your doctor may suggest something called desensitization.

You would get a small dose of the drug and then it would be raised gradually. The slow increase may get your body more used to the drug and lower your risk of an allergic reaction. It’s done in the hospital or doctor’s office.

Desensitization is not a cure. It’s only temporary. It doesn't work for everyone and it has risks. But it's one way for you to keep getting a medicine you need.

Taking Care

If you have an allergy, your doctor will advise you on how to protect yourself. Some good first steps include:


Memorize the name of the drug that you’re allergic to -- both brand names and generic. Make sure that all of your doctors, dentists, and pharmacists know about your drug allergy.

Get a medical ID bracelet or necklace with your drug allergy on it. Always wear it.

Know what to do if you have an allergic reaction. If your doctor prescribes medication for emergencies, like an EpiPen, make sure you always carry two and you know how to use it.

Questions to Ask Your Doctor

  • Do you think I have a true drug allergy?
  • Do I need drug allergy testing?
  • What can I do to protect myself?
  • Am I more likely to be allergic to other drugs?
  • Can you help me come up with a plan to help prevent problems in the future?
WebMD Medical Reference



American Academy of Allergy, Asthma, and Immunology: "Drug Allergy," "Drug Reactions and Drug Allergies."

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

UpToDate: "An approach to the patient with drug allergy," "Rapid drug desensitization for immediate hypersensitivity reactions."

World Allergy Organization: "Drug Allergies."

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