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Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN)
SJS and TEN are a severe drug reaction in which skin and mucosa detach; the most important step is to stop the culprit drug at once, followed by burn-like supportive care — usually in a burns unit — with ophthalmology involvement.
Why it matters in the exam
The classic question describes a patient who started allopurinol, carbamazepine, lamotrigine, phenytoin or a sulfonamide 1–4 weeks earlier and developed fever, skin pain, a dusky rash that peels, and sores in the mouth, eyes and genitals. The Nikolsky sign is positive — the skin detaches with gentle pressure. The distinction is by the detached area: SJS below 10%, overlap 10–30%, TEN above 30%.
The SCORTEN score for predicting mortality is also tested: age above 40, malignancy, heart rate 120 or more, detachment above 10% on admission, urea above 10 mmol/L, glucose above 14 mmol/L and bicarbonate below 20 mmol/L — one point each. Treatment: fluids (less than for a burn of the same area), wound care without removing the detached skin, pain control, infection prevention, nutrition and daily eye examination; treatments such as ciclosporin or IVIG are debated.
The differential diagnosis: staphylococcal scalded skin syndrome in children — superficial peeling without mucosal involvement; DRESS — rash, fever, eosinophilia and internal organ involvement two to six weeks after starting a drug; and erythema multiforme — "target" lesions, usually after herpes. HLA-B*15:02 testing before carbamazepine is recommended in at-risk Asian populations. The suspected drug is forbidden for life.
Key points
- Common drugs: allopurinol, carbamazepine, lamotrigine, phenytoin, sulfonamides.
- SJS below 10%, overlap 10–30%, TEN above 30%.
- Stop the drug at once, burn-like care in a suitable unit.
- SCORTEN predicts mortality.
- Early ophthalmology; the drug is forbidden for life.
Summary table
| Condition | Feature | Detached area | Treatment |
|---|---|---|---|
| SJS | Mucosa at two or more sites, dusky lesions | Below 10% | Stop the drug, support |
| SJS/TEN overlap | — | 10–30% | Burns unit or intensive care |
| TEN | Widespread detachment, positive Nikolsky | Above 30% | Burns unit, full support |
| Staphylococcal scalded skin (SSSS) | Child, mucosa spared | Superficial peeling | Antistaphylococcal antibiotics |
| DRESS | Eosinophilia, liver and kidney involvement, 2–6 weeks after the drug | No extensive detachment | Stop the drug, steroids |
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Sources
- British Association of Dermatologists guidelines for the management of Stevens–Johnson syndrome/toxic epidermal necrolysis in adults, 2016 — Assessment and supportive care
- Bastuji-Garin S et al., SCORTEN: a severity-of-illness score for toxic epidermal necrolysis (Journal of Investigative Dermatology), 2000 — The score
- Bolognia Dermatology, 5th edition (2024) — Stevens–Johnson syndrome and toxic epidermal necrolysis
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.