Clinical Features, Pathogenesis, and Management Controversies in Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

The session reviewed Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), emphasizing their clinical features, causes, pathogenesis, prognosis, and management controversies. SJS and TEN are rare, severe hypersensitivity reactions, usually drug-induced, with overlap forms distinguished by the percentage of body surface area involved. Causes may also include infections, immune disorders, toxins, and physical agents, and TEN has been linked to HLA predisposition in different populations. Clinically, SJS often begins with prodromal symptoms and prominent mucosal involvement, especially conjunctival disease, while TEN is marked by widespread pain, erythema, blistering, skin detachment, Nikolsky sign, and possible lung involvement. Histology shows epidermal necrosis with limited inflammatory infiltrate, and immunofluorescence is negative, helping with differential diagnosis. Pathogenesis is centered on a T-cell–mediated delayed hypersensitivity reaction involving CD8 cytotoxic cells, HLA associations, and inflammatory mediators such as TNF-alpha and interferon-gamma that drive keratinocyte apoptosis and necroptosis. Differential diagnoses include autoimmune blistering diseases, vasculitis, Kawasaki disease, erythema multiforme, staphylococcal scalded skin syndrome, linear IgA dermatosis, AGEP, and other erythrodermas. Mortality is about 1–5% for SJS and 25–35% for TEN, though many survivors re-epithelialize within 10–20 days, often with mucosal scarring or pigmentary changes. Management has no standardized guideline and relies on immediate withdrawal of the trigger, hospitalization, monitoring, infection control, and multidisciplinary supportive care. Systemic therapies such as corticosteroids, IVIG, cyclosporine, and TNF-alpha blockers remain controversial, and in TEN there is also debate over surgical debridement versus conservative care using the detached skin as a biologic dressing.