[Cutaneous drug reactions: diagnosis and etiology]

Drug eruptions are frequently encountered in clinical practice. Their great variety raise many problems and their complete knowledge is actually impossible. A logical approach is to describe the dermatological signs and the associated signs and symptoms. All the drugs taken by the patient and the dates of doses must be referred. Secondly, more informations may be obtained thanks to the dermatologist or a Drug Alert Registry (Regional Center of Pharmacovigilance in France). Bibliographical data varied in quality; the Vidal dictionary is often used, but Internet may be questioned. Imputability methods are well developped in France. In vivo and in vitro methods do not offer sufficient sensibility and specificity.