Drug allergies: how do we investigate them clinically?

Drug allergies are an important component of iatrogenic disorders : 10-20 % of hospitalized patients have adverse drug reactions. The presenting symptoms vary widely, most often being cutaneous, and they are sometimes severe (e.g., the Lyell syndrome and the Stevens-Johnson syndrome). The diagnosis is based on the patient's history, skin tests and provocation tests, the later carried out necessarily in specialized centers. There are as yet few reliable laboratory tests because of the occurrence of frequent false positive and false negative results. Investigation of drug allergies requires much experience, notably in allergy, dermatology and immunology. During the past three years, the European societies of dermatology, allergy and clinical immunology have organized multidisciplinary working groups which aimed to standardize the diagnostic workup. At the national level, the French societies of dermatology, internal medicine, allergy and clinical immunology have adopted these European recommendations. (C)0 2008 Elsevier Masson SAS. Tous droits reserves.