Musculoskeletal & Integumentary · Topic 9 of 11
Stevens-Johnson Syndrome, TEN & DRESS
Skin · severe cutaneous drug reactions
Stevens-Johnson Syndrome, TEN & DRESS
Skin sloughing weeks after a new drug: stop the culprit, size the detachment, and treat severe SJS/TEN like a major burn.
Key numbers
SJS < 10%, TEN > 30% BSA< 10% · 10–30% · > 30%
SCORTEN predicts TEN mortalitySCORTEN ≥ 3 → 35%
DRESS: rash, fever, eosinophilia, organ injury2–8 wk after drug
01 · Defined bySJS < 10%, TEN > 30% BSA
SJS and TEN are one disease graded by detached body surface area: SJS < 10%, SJS/TEN overlap 10–30%, TEN > 30%.
02 · DoStop the culprit drug immediately
Stop every suspected drug immediately and admit; except for mild cases, manage SJS/TEN in a burn unit or ICU with burn-type supportive care — fluids, electrolytes, daily wound care, infection control and nutrition.
03 · Defined bySCORTEN predicts TEN mortality
Score SCORTEN within 24 hours, 1 point each: age ≥ 40, cancer, HR ≥ 120, BUN > 28 mg/dL, detachment ≥ 10%, bicarbonate < 20, glucose > 250. Mortality: 0–1 ≈ 3%, 3 ≈ 35%, ≥ 5 > 90%.
01
Causes & risk factors
Why it happensSulfonamides, anticonvulsants, allopurinol, aminopenicillins, oxicam NSAIDs must knowDrugs cause most adult cases: sulfonamide antibiotics, aminopenicillins and other antibiotics, antiseizure drugs (carbamazepine, phenytoin, lamotrigine, phenobarbital, valproate), allopurinol, oxicam NSAIDs, nevirapine and immune checkpoint inhibitors.
Test HLA-B*15:02 before carbamazepine in Asian ancestryHLA alleles predict reactions: HLA-B*15:02 with carbamazepine, phenytoin or lamotrigine SJS/TEN in patients of Asian ancestry, and HLA-B*58:01 with allopurinol SJS/TEN or DRESS; consider testing before starting these drugs.
DRESS culprits: anticonvulsants, allopurinol, antibioticsDRESS is most often caused by antiseizure drugs (carbamazepine, phenytoin, lamotrigine), allopurinol and antibiotics.
02
Presentation
What you'll seeProdrome, then target lesions and sloughing bullae1–3 weeks after starting the drug, a prodrome of fever, malaise and conjunctivitis precedes dusky target macules on the face and trunk that coalesce into flaccid bullae and slough within 1–3 days (positive Nikolsky sign).
03
Diagnosis & monitoring
Work-upDRESS: rash, fever, eosinophilia, organ injury must knowDRESS (drug-induced hypersensitivity syndrome) starts 2–8 weeks (up to 12) after a new drug: fever, widespread rash, facial edema, lymphadenopathy, eosinophilia, atypical lymphocytes and internal organ involvement — liver in about 75%.
Repeat CBC, LFTs and creatinine in DRESSIn suspected DRESS order a CBC with differential and smear, liver and renal function, and repeat them — organ involvement and eosinophilia can lag the rash. Liver ≈ 75%, kidney ≈ 37%, lung ≈ 32%.
RegiSCAR ≥ 6 = definite DRESSThe RegiSCAR score grades suspected DRESS: < 2 no case, 2–3 possible, 4–5 probable, ≥ 6 definite; an eosinophil count > 1,500/mm³ scores 2 points.
04
Do right now
In this orderFirst moves
1
→Stop the culprit drug immediately
2
→SJS < 10%, TEN > 30% BSA< 10% · 10–30% · > 30%
3
→SCORTEN predicts TEN mortalitySCORTEN ≥ 3 → 35%
4
Consult ophthalmology for any eye involvement
Why each step
Stop the culprit drug immediatelyStop every suspected drug immediately and admit; except for mild cases, manage SJS/TEN in a burn unit or ICU with burn-type supportive care — fluids, electrolytes, daily wound care, infection control and nutrition.
SJS < 10%, TEN > 30% BSASJS and TEN are one disease graded by detached body surface area: SJS < 10%, SJS/TEN overlap 10–30%, TEN > 30%.
SCORTEN predicts TEN mortalityScore SCORTEN within 24 hours, 1 point each: age ≥ 40, cancer, HR ≥ 120, BUN > 28 mg/dL, detachment ≥ 10%, bicarbonate < 20, glucose > 250. Mortality: 0–1 ≈ 3%, 3 ≈ 35%, ≥ 5 > 90%.
Consult ophthalmology for any eye involvementOphthalmology consultation and specialized eye care are mandatory when the eyes are involved, to prevent scarring and vision loss.
05
Management
OrdersConsider cyclosporine 3–5 mg/kg/day or etanerceptImmunomodulation is controversial: cyclosporine 3–5 mg/kg/day shortens active disease and may lower mortality; etanercept may lower mortality; IVIG, systemic glucocorticoids and plasmapheresis have conflicting evidence.
No prophylactic antibiotics; treat proven infectionIsolate the patient and do not give prophylactic systemic antibiotics; start antibiotics promptly when bacterial infection or sepsis is suspected, since infection and multiorgan failure drive deaths.
DRESS: stop drug, give systemic corticosteroidsTreat DRESS by stopping the culprit and giving systemic corticosteroids first line; cyclosporine is the second-line or steroid-sparing option. Symptoms can persist or relapse for weeks after the drug is stopped.
06
Red flags & don'ts
Avoid harmMucosa, eyes and airway slough too complicationOral erosions, keratoconjunctivitis and genital lesions accompany most cases; bronchial epithelium can slough (dyspnea, pneumonia, hypoxemia), and glomerulonephritis or hepatitis may develop. Survivors often have lasting eye, oral and psychological sequelae.
Never rechallenge; desensitization is contraindicated avoidAvoid the culprit and cross-reacting drugs for life and record the reaction prominently; desensitization must not be attempted after SJS/TEN or DRESS.
07
SJS/TEN or DRESS?
Commonly confused| Onset after the drug | 1–3 weeks |
|---|---|
| Defining finding | Epidermal detachment, graded by % BSA |
| Skin | Dusky target lesions → flaccid bullae, sheet-like detachment, Nikolsky positive |
| Mucosa | Painful erosions in most cases |
| Internal organs | Eyes, airway epithelium, kidney, liver |
| Key treatment | Stop drug; burn-unit supportive care; immunomodulators debated |
08
Commonly confused
Tell apartBiopsy shows full-thickness epidermal necrosisDiagnosis is clinical; skin biopsy showing necrotic epithelium confirms it. Staphylococcal scalded skin syndrome spares mucous membranes; toxic shock has more multiorgan involvement; exfoliative erythroderma spares mucosa and is less painful.
09
More detail
ReferenceShow 4 reference facts
Adult SJS/TEN mortality can reach 25–35%, lower with early treatment; DRESS mortality in hospitalized US patients is about 3%.
SJS/TEN is a CD8 T-cell–mediated cytotoxic reaction; granulysin and Fas–Fas ligand signaling drive keratinocyte death. DRESS often features HHV-6 or other herpesvirus reactivation 2–4 weeks after onset, linked to relapse.
Non-drug causes of SJS include Mycoplasma pneumoniae infection (the usual cause in children), vaccination and graft-versus-host disease; HIV and lupus raise incidence and severity.
The DRESS rash is usually a polymorphous maculopapular eruption (about 85%) with facial edema (about 76%); mucous membranes are involved in about 56%, more mildly than in SJS/TEN.
Find the new drug, stop it, and never give it again — detachment under 10% is SJS, over 30% is TEN.
Sources · Merck Manual Professional — Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) · Alotaibi M et al. Drug-Induced Reaction With Eosinophilia and Systemic Symptoms: A Review. Cureus 2023;15(3):e35701 · Sasidharanpillai S et al. RegiSCAR DRESS Validation Scoring System and Japanese Consensus Group Criteria for Atypical DiHS: A Comparative Analysis. Indian Dermatol Online J 2022;13(1):40–45 · Merck Manual Professional — Drug Hypersensitivity (DRESS; HLA risk table; desensitization) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).