The pathogenesis of DRESS syndrome has not been elucidated. Different mechanisms have been proposed, including detoxification defects leading to reactive metabolite formation and subsequent immunological reactions, slow acetylation and reactivation of Human Herpes Virus (HHV-6-7) and EBV . Severe DRESS syndrome has also been reported following infection with or reactivation of HHV-6 . CMV and paramyxovirus have been reported as the other viral agents associated with DRESS syndrome. Although it is thought that there is a genetic predisposition to adverse reactions, no genetic factor responsible for the syndrome has been identified yet .