A 28-year-old woman presents with fever, severe oral ulceration, and a rapidly spreading erythematous rash involving <10% of body surface area with target lesions and mucosal involvement. She had started trimethoprim-sulfamethoxazole 5 days ago for a urinary tract infection. What is the drug of choice for management of this condition?

Explanation

## Diagnosis and First-Line Management The clinical presentation describes **Stevens-Johnson Syndrome (SJS)** — characterized by: - Fever and mucosal involvement (oral, ocular, genital) - Target lesions with true three-zone morphology - Involvement of <10% body surface area (BSA) - Clear temporal relationship to drug exposure (TMP-SMX) ### First-Line Treatment: IVIG **Key Point:** Intravenous immunoglobulin (IVIG) is the preferred first-line immunomodulatory therapy for SJS/TEN, with the strongest evidence base and most favorable risk-benefit profile in current practice. **High-Yield:** IVIG mechanism in SJS/TEN: - Blocks Fas-FasL interactions on keratinocytes, halting apoptosis-driven epidermal necrosis - Reduces TNF-α and IL-6 production - Dosing: 2 g/kg total over 3–5 days (0.4–0.5 g/kg/day) ### Why IVIG Over Other Options | Intervention | Role in SJS/TEN | Evidence | Notes | |---|---|---|---| | **IVIG** | First-line immunomodulator | Level 1 (RCTs, meta-analyses) | Early use (within 72 hrs) preferred | | Systemic corticosteroids | Controversial; use with caution | Level 2–3 | Increased infection risk, delayed wound healing; high-dose monotherapy generally avoided | | Cyclosporine | Second-line if IVIG fails or contraindicated | Level 2; case series | Emerging evidence supports early use | | Infliximab | Salvage therapy | Level 3; case reports | Limited data | **Clinical Pearl:** Systemic corticosteroids were historically the mainstay of SJS/TEN treatment. Current consensus (Harrison's 21e, Fitzpatrick's Dermatology) advises **against high-dose monotherapy** due to increased infection risk and impaired wound healing; low-dose adjunctive use remains debated. IVIG is now the preferred immunomodulatory agent. This distinction is a common NEET PG trap. **Note on Option A:** The dose listed (methylprednisolone 1 g IV daily) represents pulse/high-dose steroid therapy — a regimen associated with the highest risk of infectious complications in SJS/TEN and not recommended as first-line management. **Warning:** Do NOT confuse SJS management with erythema multiforme minor (which may respond to topical steroids alone). SJS requires systemic immunomodulation and supportive care in a specialized unit. ### Supportive Care Essentials - Immediate withdrawal of the offending drug (TMP-SMX in this case) - Nursing care in ICU/burn unit - Ophthalmology and ENT review - Fluid and electrolyte management - Infection prophylaxis [cite: Harrison's Principles of Internal Medicine 21e, Ch 56; Fitzpatrick's Dermatology 9e]