A 28-year-old woman presents to the emergency department with a 5-day history of fever, malaise, and a rapidly spreading erythematous rash. She had started oral trimethoprim-sulfamethoxazole (TMP-SMX) 7 days ago for a urinary tract infection. On examination, she has widespread erythematous macules and papules involving the trunk, face, and proximal limbs. Oral mucosa shows erosions and bleeding. Nikolsky sign is positive on the trunk. Laboratory investigations show WBC 8,500/μL, platelets 180,000/μL, and normal liver and renal function. Skin biopsy shows full-thickness epidermal necrosis with subepidermal blister formation. What is the most appropriate immediate management?

Explanation

## Clinical Diagnosis: Stevens-Johnson Syndrome (SJS) ### Key Diagnostic Features **Key Point:** This patient meets SJS criteria: fever, mucosal involvement (oral erosions), positive Nikolsky sign, and skin biopsy showing full-thickness epidermal necrosis with subepidermal blistering. The temporal relationship to TMP-SMX initiation (7 days prior) is classic — SJS typically develops 1–3 weeks after drug exposure. ### Severity Assessment | Feature | SJS | TEN | |---------|-----|-----| | Body surface area (BSA) involved | < 10% | ≥ 30% | | Mucosal involvement | Frequent | Frequent | | Systemic involvement | Mild to moderate | Severe | | Mortality | 1–5% | 25–50% | **Clinical Pearl:** This patient has SJS (BSA < 10% based on trunk, face, proximal limbs) with significant mucosal involvement and positive Nikolsky sign, indicating severe epidermal damage. ### Management Algorithm ```mermaid flowchart TD A[SJS/TEN Diagnosis Confirmed]:::outcome --> B[Immediate Drug Withdrawal]:::action B --> C[Assess BSA & Severity]:::decision C -->|SJS or TEN| D[Hospitalization in ICU/Burn Unit]:::action D --> E[Supportive Care]:::action E --> F1[Fluid & Electrolyte Management] E --> F2[Temperature Control] E --> F3[Infection Prevention] D --> G{Severe/Rapidly Progressive?}:::decision G -->|Yes| H[IVIG 2 g/kg over 3-5 days OR Systemic Corticosteroids]:::action G -->|No| I[Supportive Care Alone]:::action H --> J[Monitor for Complications]:::outcome I --> J ``` ### Rationale for Correct Answer **High-Yield:** The cornerstone of SJS/TEN management is: 1. **Immediate discontinuation** of the offending drug (TMP-SMX) 2. **Hospitalization** in a specialized unit (burn ward or ICU) for close monitoring and supportive care 3. **Aggressive fluid and electrolyte management** (similar to burn care) 4. **Immunomodulatory therapy** (IVIG or systemic corticosteroids) in severe or rapidly progressive cases **Key Point:** Systemic corticosteroids are controversial but increasingly used in early SJS/TEN, particularly when started within 7–10 days of onset. IVIG is an alternative with emerging evidence of efficacy. Both can be considered based on disease severity and progression rate. ### Why Supportive Care Alone Is Not Sufficient **Warning:** Topical corticosteroids alone are inadequate for SJS with mucosal involvement and positive Nikolsky sign. This patient requires systemic intervention and specialized monitoring to prevent complications (sepsis, electrolyte imbalance, respiratory involvement). ### Mnemonic for SJS/TEN Management: **DISC** - **D** — Discontinue offending drug immediately - **I** — ICU/specialized unit admission - **S** — Supportive care (fluids, temperature, infection control) - **C** — Consider IVIG or corticosteroids in severe cases [cite:Robbins 10e Ch 25]