DRESS syndrome is distinguished from other severe cutaneous adverse reactions by which pathognomonic feature?

• A Mucous membrane involvement in >90% of cases
• B Histological interface dermatitis with full-thickness epidermal necrosis
• C Onset within 48 hours of drug exposure
• D Reactivation of human herpesvirus-6 (HHV-6) detected by rising serology ✓

Explanation

DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms) is characterised by HHV-6 reactivation, a feature not seen in SJS/TEN or other drug reactions, thought to reflect immune reconstitution driving viral replication. Mucous membrane involvement is minor or absent in DRESS. Onset is typically 2–8 weeks after initiating the culprit drug (not 48 hours). Full-thickness epidermal necrosis on histology is the hallmark of TEN, not DRESS.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.