About Allergy De-Labelling

Oral Drug Challenge

Oral drug challenge is a way of proving with certainty that someone is not allergic to a given drug. It is usually done after skin testing has indicated that a person is not likely to be allergic. 

In oral drug challenge, a person is re-exposed to a small dose of the drug in a controlled environment and then monitored. Sometimes increasing doses of the drug are given sequentially.

If no reaction occurs, the challenge is said to be negative, and the drug is proven safe.

If any signs of allergy occur, the test is said to be positive, and the allergy is confirmed. Like all allergy, these signs may include rash, wheeze, low blood pressure, nausea, swelling of the face  etc.

If the symptoms are significant, then usual treatment for allergy (including antihistamines and adrenaline) will be given until symptoms resolve.

Drug challenge is not without risk, but the risks are small. The intention of drug challenge is that we expect to confirm a negative result and rule out an allergy entirely.