Stevens-Johnson Syndrome / Toxic Epidermal Necrolysis (SJS/TEN)
A life-threatening severe cutaneous adverse reaction with painful epidermal necrosis or detachment and prominent mucosal disease; treat it as a skin-failure emergency until specialist assessment excludes it.
Definition
Stevens-Johnson syndrome and toxic epidermal necrolysis are severe cutaneous adverse reactions characterised by epidermal necrosis or detachment, systemic illness and mucosal involvement. SJS involves less than 10% epidermal detachment, SJS/TEN overlap 10% to 30% and TEN more than 30%.
First principles
Painful skin loss plus mucosal disease is a medical emergency
SJS/TEN usually begins with fever and systemic illness followed by a painful dusky or purpuric eruption, blistering, epidermal detachment and erosions of two or more mucosal sites. The skin barrier, eyes, mouth, airway, respiratory tract and genitourinary tract may all be affected, so early senior assessment and transfer are more important than completing a prolonged differential in the community.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.

