A 9-year-old girl recovering from a cold sore develops dusky red macules that evolve into lesions with three concentric zones: a central dusky blister, a pale edematous ring, and an outer erythematous ring. Lesions are symmetric on the backs of both hands and extensor forearms, with mild lip crusting. There is no mucosal blistering elsewhere and she is hemodynamically stable. What is the most likely diagnosis?

• A Stevens-Johnson syndrome
• B Kawasaki disease
• C Bullous pemphigoid
• D Erythema multiforme minor triggered by herpes simplex virus ✓

Explanation

Classic target lesions in three concentric zones, symmetric acral distribution, preceding herpes labialis, and minimal involvement confined to one mucosal surface define erythema multiforme minor. Stevens-Johnson syndrome is distinguished by severe widespread mucosal involvement of at least two surfaces, constitutional toxicity, and detachment of skin, none of which is present here. Bullous pemphigoid is a tense-bullous autoimmune disease of the elderly, and Kawasaki disease presents with prolonged fever and other systemic criteria.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.