Stevens-Johnson Syndrome (SJS) & Toxic Epidermal Necrolysis (TEN)
SJS and TEN are life-threatening, drug-induced mucocutaneous reactions characterized by extensive keratinocyte necrosis and dermo-epidermal separation.
Distinction by Body Surface Area (BSA)
| Condition | BSA Involvement |
|---|---|
| SJS | < 10% |
| SJS/TEN Overlap | 10% – 30% |
| TEN | > 30% |
Key Clinical Features
- Triggers: Commonly associated with “SATAN” drugs: Sulfonamides, Allopurinol, Tetracyclines, Anticonvulsants (phenytoin, carbamazepine), and NSAIDs.
- Presentation: Starts with flu-like symptoms, followed by rapid, painful sheet-like skin detachment. Severe involvement of at least two mucous membranes (oral, ocular, genital) is characteristic.
- Nikolsky Sign: Positive (skin slides off with lateral pressure).
High-Yield Exam Pearl:
- Management: Immediate withdrawal of the offending drug is the most important step. Supportive care in a burn unit is standard.
- Prognosis: Use the SCORTEN score (an acronym for the 7 prognostic factors: Age, Heart rate, Cancer, Initial BSA, BUN, Bicarbonate, Glucose) to calculate mortality risk.