Drug Allergy

What is a drug allergy?

A drug allergy is a condition where your immune system reacts to a medication like it is a harmful substance, triggering an allergic reaction. Drug allergies are more likely with medications you take frequently, and when the medication is injected or rubbed on your skin, and less likely with medications taken orally.

Some medications are more likely to trigger an allergic response, including:

• Penicillin and other antibiotics
• Non-steroidal anti-inflammatory drugs like aspirin and ibuprofen
• Anticonvulsants
• Chemotherapy

What are some common drug allergy symptoms?

Drug allergies aren't side effects. When your immune system identifies a medication as a threat, it releases histamines and other chemicals to fight off the perceived threat. That causes symptoms like:

• Skin rashes and hives
• Itchy skin
• Breathing problems
• Swelling
• Anaphylaxis

If you think you’re having an allergic reaction to a medication, stop taking it. If you show signs of anaphylaxis, including swelling, hives, low blood pressure, or shock, seek emergency medical care. Unlike other allergic reactions, anaphylaxis affects more than one body system at the same time and can be fatal.

How are drug allergies diagnosed?

Your doctor at Allergy and Asthma Specialists of Greater Washington diagnoses drug allergies with a comprehensive exam, skin tests, blood tests, and oral drug challenges. Your doctor will ask you questions like:

• When your symptoms began and how long they lasted
• What kind of symptoms you experienced
• What other medications, vitamins, and supplements you were taking

During a skin test, your skin is exposed to a small, diluted amount of the suspect drug with an injection, a scratch test, or a patch. If you’re allergic to the drug, you develop a small, itchy, red bump on the test site.

Your doctor may suggest an oral drug challenge where you take a medication, and they observe you for signs of an allergic reaction. This is an alternative if a skin or blood test isn’t available or is inconclusive.

How are drug allergies treated?

In most cases, if you have a drug allergy, you stop taking the medication and avoid it in the future. Your doctor at Allergy and Asthma Specialists of Greater Washington may also prescribe medications to manage your symptoms like antihistamines, corticosteroids, and epinephrine.

If you’re concerned about a drug allergy, call or make an appointment online today.