Skin tests, including patch tests (PTs), prick tests and intradermal tests (IDTs), are useful to identify the culprit(s) of a cutaneous adverse drug reaction (CADR), and to determine (a) safer alternative drug(s). PTs have a low sensitivity but are valuable to investigate maculopapular exanthema (MPE), as well as severe CADR, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and (especially) acute generalized exanthematous pustulosis (AGEP) and drug rash with

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... ia and systemic symptoms (DRESS). To ensure their specificity at least 10 controls should be performed. Prick tests are mainly used in the evaluation of immediate-type hypersensitivity, and can be performed with all drugs, except opiates. IDTs can be used to explore immediate and delayed-type hypersensitivity, if an injectable form of the drug exists. Except for SJS/TEN, IDTs should be performed by injecting 0.02 mL of the drug. We here provide a practical up-to-date review on the use of these skin tests in the work-up of CADRs. Numerous negative controls for drug PTs, prick tests and IDTs, as well as criteria for the immediate and delayed positivity of the latter, are included. It should be emphasized that a negative result never excludes the potential responsibility of a drug in a CADR. This article is protected by copyright. All rights reserved.