Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN)
Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are severe, life-threatening mucocutaneous reactions characterized by epidermal detachment, multisite mucositis, and systemic symptoms, typically triggered by medications or infections. 1, 2
Clinical Features
Prodromal Phase
- Initial "flu-like" symptoms including fever, malaise, and upper respiratory tract symptoms typically precede the eruption by several days 1, 2
- Ocular inflammation may develop before skin signs appear 2
- Cutaneous pain is a prominent early feature that should alert clinicians to impending epidermal necrolysis 1
Mucocutaneous Manifestations
- Early and prominent involvement of mucous membranes (eyes, mouth, nose, genitalia) leading to erosive and hemorrhagic mucositis 1, 2
- Skin manifestations progress to:
- Large areas of confluent erythema
- Tender lesional skin with positive Nikolsky sign (epidermis peels back with minimal shearing force)
- Blistering with necrotic epidermis separating from underlying dermis
- Extensive necrolysis resulting in detachment of epidermal sheets 1
Classification Based on Body Surface Area (BSA) Involvement
- SJS: <10% BSA detachment
- SJS/TEN overlap: 10-30% BSA detachment
- TEN: >30% BSA detachment 2
Etiology
Common Triggers
Medications (89.7% of cases) 3:
Infections:
Genetic susceptibility:
Diagnosis
Clinical Diagnosis
- Based on characteristic presentation with skin and mucosal involvement
- History of exposure to potential triggers (medications or infections) 2
Confirmatory Testing
- Skin biopsy showing:
- Subepidermal cleavage
- Variable epidermal damage from individual cell apoptosis to confluent epidermal necrosis
- Basal cell vacuolar degeneration
- Mild perivascular lymphocytic and histiocytic infiltrate 2
Differential Diagnosis
- Staphylococcal Scalded Skin Syndrome (SSSS) - lacks mucosal involvement
- Erythema Multiforme Major (EMM) - distinct from SJS/TEN
- Immunobullous disorders (pemphigus, pemphigoid)
- Acute generalized exanthematous pustulosis (AGEP)
- Disseminated fixed bullous drug eruption 1, 4
Management
Immediate Interventions
- Stop the suspected culprit drug immediately 2
- Transfer to a specialized center with experience in managing SJS/TEN 2
Supportive Care (Cornerstone of Management)
- Fluid and electrolyte management
- Wound care
- Nutritional support
- Pain management 2
Specific Treatments
- Immunomodulatory therapy may be considered, though evidence is limited:
Prognosis and Complications
Mortality
- SJS: 1-5% mortality rate
- TEN: 25-35% mortality rate
- Higher risk in elderly patients and those with larger surface area of epidermal detachment 4, 5
- Observed mortality (14.7%) may be lower than predicted by SCORTEN (21%) with appropriate management 3
Long-term Sequelae
- Skin: pigmentation changes, scarring
- Ocular: vision impairment, dry eyes
- Mucosal: oral, dental, respiratory, and urogenital problems
- More than 50% of TEN survivors experience long-term sequelae 1, 2, 4
Recurrence
- More common in children (up to 18% of cases)
- Higher risk when triggered by infections rather than drugs 1
Prevention
- Avoid culprit drugs in patients with history of SJS/TEN
- Consider genetic testing for HLA associations in certain populations before prescribing high-risk medications 2
- Prophylactic strategies for recurrent HSV-associated SJS may include antiviral therapy 2
SJS/TEN represents a true dermatological emergency requiring rapid diagnosis, immediate withdrawal of the culprit drug, and specialized supportive care to reduce mortality and long-term morbidity.