[Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): a review]

DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms), also known as hypersensitivity syndrome (HSS), is a severe and potentially life-threatening drug reaction. The worldwide rate of mortality is about 10 %, its incidence is increasing. Drugs that most frequently induce DRESS are aromatic anticonvulsive drugs (carbamazepine, lamotrigine, phenobarbital), and more recently new retroviral therapies. The pathogenesis of DRESS is not yet fully understood, but is certainly multifactorial involving a combination of immune reactions, ethnic predisposition, genetically determined enzyme deficiencies and reactivation of herpes viruses (HHV-6, HHV-7, EBV, CMV). Because of the involvement of the skin and internal organs, the clinical picture can be very variable. No specific clinical, histologic or laboratory parameter is available, so the diagnosis has to rely on the clinical appearance. The long latency period between start of drug intake and the initial manifestation of DRESS and the successive onset of skin and organ involvement complicates the early diagnosis. Although or even because DRESS represents a diagnostic challenge, detailed knowledge about this disease is of utmost importance to enable early therapeutic actions.