Usefulness of drug patch testing in cutaneous drug allergy: what is new?

Recent studies have emphasized the value of drug patch tests, in addition to, prick and intradermal tests to determine the molecule responsible for cutaneous adverse drug reactions (CADR), also known as drug eruptions. The value of drug patch tests depends on the clinical features of the CADR, and they are valuable in the investigation of drug reactions, such as generalized eczema, systemic contact dermatitis, maculopapular rashes, toxic epidermal necrolysis, and fixed drug eruptions. Their sensitivity also depends on the particular drug involved. Guidelines for performing prick, ID and patch tests, published in 2001, are analyzed in the present article. We also report on the information published more recently on how to perform the tests, how to interpret them, new drugs reported to yield positive reactions and, finally, how to define the relevance and the specificity of drug patch tests in the workup of cutaneous drug allergies. [Copyright &y& Elsevier]