Currently, there are very few valid skin tests for the diagnosis of drug allergy. Drugs for which there are accepted testing protocols include penicillin and Amoxicillin, local anesthetics, muscle relaxants for anesthesia (suxamethonium), and insulin. While other drugs may be tested, there is less experience with these agents and the results may be more difficult to interpret.
Penicillin skin testing, which is the most frequently performed antibiotic skin test, typically consists of a battery of tests to penicillin, amoxicillin, and the metabolic breakdown products of penicillin. If these tests are all negative, the risk of having an immediate allergic reaction to penicillin, such as hives or anaphylaxis, is on the order of only 3% or less.