Stevens-Johnson syndrome and toxic epidermal necrolysis — branching viva

Branching structured-oral viva on Stevens-Johnson syndrome and toxic epidermal necrolysis: the SJS, overlap and TEN classification by body-surface-area detachment, the drug-specific CD8-positive T-cell and granulysin pathophysiology, the anticonvulsant, sulfonamide, allopurinol and nevirapine culprits and the HLA-B15:02 and HLA-B58:01 pharmacogenetics, SCORTEN, the distinction from staphylococcal scalded skin syndrome and Mycoplasma-induced rash and mucositis, and the supportive-care-centred management with the no-proven-benefit position on immunomodulation.

branching clinical structured oral5 min readVerification in progress

Prompt

You are the general paediatric registrar in the emergency department. A 9-year-old girl started carbamazepine six weeks ago and now has fever, painful red eyes, crusted bleeding lips and dusky target lesions with sheet-like peeling of about 12 percent of her body surface area. The examiner asks you to take the candidate through the recognition, classification, severity scoring, immediate and stepwise management, and family counselling.

Opening question

Examiner: Take me through this child. What is the diagnosis, and what is your immediate frame? ^[6]

Candidate: This is Stevens-Johnson syndrome-toxic epidermal necrolysis overlap, a severe drug-induced mucocutaneous reaction. The keys are the carbamazepine started six weeks ago, the atypical target lesions, the sheet-like detachment of about 12 percent of body surface area, the positive Nikolsky sign, and the mucositis at two or more sites — the eyes and the mouth. My immediate frame is three things: stop the culprit drug at once, grade the severity with SCORTEN and admit to a burn-capable setting, and involve ophthalmology within hours to protect the eye. ^[6] ^[1]

Examiner: How do you classify this spectrum? ^[1]

Candidate: By the percentage of body-surface-area with epidermal detachment. Stevens-Johnson syndrome is under 10 percent, SJS-TEN overlap is 10 to 30 percent, and toxic epidermal necrolysis is more than 30 percent. All three share atypical target lesions, a positive Nikolsky sign and mucositis at two or more sites. This child, at 12 percent, is in the overlap band. ^[1]

References8Show

[1]Bastuji-Garin S; Fouchard N; Bertocchi M; Roujeau JC; et al SCORTEN: a severity-of-illness score for toxic epidermal necrolysis. J Invest Dermatol, 2000.PMID 10951229
[3]Lonjou C; Borot N; Sekula P; Ledger N; et al A European study of HLA-B in Stevens-Johnson syndrome and toxic epidermal necrolysis related to five high-risk drugs. Pharmacogenet Genomics, 2008.PMID 18192896
[4]Chung WH; Hung SI; Hong HS; Hsih MS; et al Medical genetics: a marker for Stevens-Johnson syndrome. Nature, 2004.PMID 15057820
[5]Canavan TN; Mathes EF; Frieden I; Shinkai K Mycoplasma pneumoniae-induced rash and mucositis as a syndrome distinct from Stevens-Johnson syndrome and erythema multiforme: a systematic review. J Am Acad Dermatol, 2015.PMID 25592340
[6]Halevy S; Ghislain PD; Mockenhaupt M; Fagot JP; et al Allopurinol is the most common cause of Stevens-Johnson syndrome and toxic epidermal necrolysis in Europe and Israel. J Am Acad Dermatol, 2008.PMID 17919772
[9]Zimmermann S; Sekula P; Venhoff M; Motschall E; et al Systemic Immunomodulating Therapies for Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A Systematic Review and Meta-analysis. JAMA Dermatol, 2017.PMID 28329382
[10]AlFada M; Alotaibi H; Alsharif S; Alani AH; et al Systematic review, methodological appraisal, and recommendation mapping of clinical practice guidelines for managing patients with Stevens-Johnson syndrome and toxic epidermal necrolysis. J Dermatolog Treat, 2025.PMID 40010698
[12]Chung WH; Hung SI Recent advances in the genetics and immunology of Stevens-Johnson syndrome and toxic epidermal necrosis. J Dermatol Sci, 2012.PMID 22541332