Drug Reaction with Eosinophilia and Systemic Symptoms: an update on pathogenesis.

The syndrome termed 'Drug Reaction with Eosinophilia and Systemic Symptoms' (DRESS) is an unpredictable, life-threatening condition associated with adverse reactions to therapy. Although the etiology of DRESS is poorly understood, genetic susceptibility markers have been identified within the HLA complex and there are several prevailing models of pathogenesis. Modification of host antigens by haptens (drugs or their metabolites), or non-covalent drug binding to endogenous proteins (the p-i concept), may drive pro-inflammatory immune responses in patients. Alternatively, a viral trigger for DRESS has been proposed based on the concomitant detection of herpesviruses and the recent demonstration of Epstein-Barr virus-specific immune responses in DRESS patients. In the present review, we discuss the latest findings concerning the pathogenesis of drug reactions and known risk factors for DRESS.