A 40-year-old man with acute inflamed tinea pedis develops intensely pruritic vesicles symmetrically over the sides of both fingers and palms. KOH examination and bacterial culture from the hand lesions are negative. The most likely diagnosis is:

• A Kerion
• B Dermatophytid (id) reaction ✓
• C Disseminated cutaneous candidiasis
• D Majocchi granuloma

Explanation

An id reaction is a secondary hypersensitivity response to circulating fungal antigens from a distant inflammatory focus such as tinea pedis. It presents as symmetrical pruritic vesicles on the hands and sides of fingers, and the lesions themselves are sterile: fungus cannot be demonstrated in them. Treatment is directed at the primary infection plus symptomatic care. Majocchi granuloma is a perifollicular granulomatous tinea from intrafollicular fungi, and kerion is inflammatory scalp infection.

Reference: Fitzpatrick's Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.