Skin tests are the most readily available tools for the evaluation of drug hypersensitivity reactions. A skin test reaction to a drug tested in a non-irritative concentration is indicative of a drug allergy and a potentially harmful drug provocation test can be avoided. New knowledge about and better standardization of skin tests have evolved. For example, more data has been gathered regarding non-irritative skin test concentrations and the negative predictive value of skin tests.

It has been shown that the recommended concentrations of tests can vary depending on the type of mechanism assumed (immediate and delayed hypersensitivities).

It is important to provide a detailed update of the methods to be followed in order to harmonize practices and carry out multicenter studies, to determine when tests are essential before carrying out a drug challenge based on risk assessment, and to specify whether the thresholds to be respected are different when the mechanism is supposed to be an immediate or delayed hypersensitivity.