A 28-year-old woman presents to the emergency department with a 3-day history of fever, malaise, and widespread painful blistering of the skin and oral mucosa. She had started taking trimethoprim-sulfamethoxazole for a urinary tract infection 10 days ago. On examination, she has extensive erythematous macules and target lesions involving >30% of her body surface area, with painful erosions of the lips, tongue, and pharynx. Nikolsky sign is positive. Blood pressure is 100/65 mmHg, and she appears unwell. What is the most appropriate immediate management?

Explanation

## Diagnosis and Immediate Management of TEN **Key Point:** This patient has Toxic Epidermal Necrolysis (TEN), a life-threatening drug reaction characterized by >30% body surface area involvement with full-thickness epidermal necrosis and positive Nikolsky sign. The trimethoprim-sulfamethoxazole is the clear culprit (typical onset 10–14 days post-exposure). **High-Yield:** Immediate discontinuation of the offending drug is the SINGLE most important intervention in TEN. Mortality increases significantly if the drug is continued beyond the first 24–48 hours of diagnosis. ## Management Algorithm ```mermaid flowchart TD A[Suspected TEN/SJS]:::outcome --> B[Discontinue offending drug immediately]:::urgent B --> C[Transfer to ICU/burn unit]:::action C --> D[Supportive care: fluids, electrolytes, nutrition]:::action D --> E[Skin care: topical antibiotics, non-adherent dressings]:::action E --> F{Rapidly progressive?}:::decision F -->|Yes, high mortality risk| G[Consider adjunctive IVIG or systemic corticosteroids]:::action F -->|Stable| H[Continue supportive care, monitor for sepsis]:::action G --> I[Outcome: mortality 25–50% even with treatment]:::outcome ``` ## Why Immediate Drug Withdrawal is Critical | Aspect | Detail | |--------|--------| | **Timing** | Drug discontinuation within 24–48 hrs of diagnosis significantly improves survival | | **Pathophysiology** | Continued drug exposure perpetuates cytotoxic T-cell activation and keratinocyte apoptosis | | **Mortality** | ~50% if drug continued; ~25% if stopped early | | **Evidence** | No randomized trial proves systemic corticosteroids reduce mortality; supportive care is cornerstone | **Clinical Pearl:** TEN is a medical emergency with mortality 25–50% even with optimal care. The patient requires ICU-level care with careful fluid management (similar to severe burn management), nutritional support, and prevention of secondary infection. Systemic corticosteroids remain controversial and are NOT first-line; IVIG may be considered as adjunctive therapy in rapidly progressive cases, but evidence is weak. **Warning:** Delaying drug discontinuation while awaiting biopsy or starting corticosteroids first is a fatal mistake. Biopsy can be done after stabilization if diagnosis is uncertain, but clinical suspicion of TEN warrants immediate drug withdrawal.