• Prodrome (1-14 days): fever, ocular burning, odynophagia
• Mucosal involvement: >90% of cases
• Lesions are tender/burn
• Trunk 🡪 spreads to neck, face, proximal upper extremities (opposite of EM) distal arms/legs often spared
• Systemic manifestations: fever, lymphadenopathy, hepatitis, cytopenias, and cholestasis (vanishing bile duct syndrome)
• Other mucosal linings 🡪 respiratory tract in ~25% (TEN); ± GI lesions (esophagitis, diarrhea); conjunctivitis
• The major cause of death is infection (and fluid loss in TEN)
• Delayed discontinuation of suspected drug worsens the prognosis
• Delayed complications:
  • Ocular (corneal ulceration, uveitis)
  • Cutaneous (scarring, eruptive melanocytic nevi)
  • Persistent erosions of trachea/mucous membranes
  • Tubular necrosis
  • Nail dystrophy
  • Diffuse hair loss

Skin lesions

• Non palpable macular atypical targets 
• Tender dusky red or purpuric macules of irregular size and shape ± coalesce 
• As disease progresses into full thickness necrosis (hours to days) lesions become gray 
• Wet cigarette paper-like, reveals large raw areas of bleeding dermis (scalding)
• Positive Nikolsky and Asboe-Hansen signs

SCORTEN is used to predict severity-of-illness (1 point each):

• Age > 40 years old
• Tachycardia > 120 beats per minute
• Malignancy
• Body surface area on day 1 > 10%
• Serum urea > 10 mmol/L
• Serum bicarbonate <20 mmol/L
• Serum glucose > 14 mmol/L

Mortality rate: 

• SCORTEN 0–1: 3.2%
• SCORTEN 2: 12.1%
• SCORTEN 3: 35.8%
• SCORTEN 4: 58.3%
• SCORTEN ≥5: 90%