**1. Introduction**

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) belong to severe cutaneous adverse drug reactions (SCARs). Although their incidence is rare, around 2–3 per million per year, their mortality rate can be up to 5–30%. These reactions are life-threatening due to internal organ failures, disseminated skin detachment, and necrolysis. The most common causative medicines inducing SJS/TEN are allopurinol, carbamazepine, sulfamethoxazole, and other antibiotics, even traditional medicine. The pathogenesis of SJS/TEN is not fully understood, but some immunological and genetic factors are believed to be involved. The treatment of SJS/TEN is still controversial in which several studies showed variable results, including systemic corticosteroid, cyclosporine, intravenous immunoglobulin (IVIG), etanercept, thalidomide, and plasmapheresis.
