Differences between Stevens-Johnson syndrome versus toxic epidermal necrolysis

Background: To retrospectively review the outcomes of two rare cutaneous diseases, Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), and to question the practice of averaging the mortality rate on the assumption that they are one disease. Methods: A retrospective chart review of all patients diagnosed with SJS and TEN by a dermatologist between January 1, 2000, and January 1, 2020, at our institution was performed. Seventy-one patients were identified (21 pediatric and 50 adults). Pathology slides from 32 adult patients (64%) were evaluated by a blinded board-certified dermatopathologist. Results: Of the adult patients, 31 had SJS, two had SJS-TEN overlap, and 17 had TEN. All 21 patients in the pediatric group were diagnosed with SJS mainly caused by Mycoplasma. Mortality rates were 6.5% for SJS among adults and 35.3% for TEN. Chemotherapy-induced TEN is a trigger with 50% mortality. Conclusions: SJS was more common in adults and pediatric cases than TEN (3:1) and had a much better prognosis and outcome. Combining and averaging the mortality rates of TEN and SJS are not advised as SJS is mainly a mucocutaneous disorder with good prognosis versus TEN, a systemic toxicity of multiple organs with deep skin detachment.