'Clues' for the histological diagnosis of tinea: how reliable are they?

Abstract

Dermatophyte infections of the skin surface (tinea corporis and tinea faciei) mostly present as erythematous scaly papules that gradually progress to annular or nummular red patches or plaques, frequently with central clearing and peripheral scales1. Although less common, pustules, vesicles, or large blisters may be clinical features. Many histological clues for the diagnosis of dermatophyte infection have been proposed, including neutrophils in the stratum corneum, compact orthokeratosis, papillary dermal edema, and the presence of fungal hyphae between 2 zones of cornified cells (called the sandwich sign)1,2. This study was performed to evaluate the reliability and clinical value of the clues for the histological diagnosis of tinea corporis and tinea faciei. Eighteen skin biopsy samples were retrieved from histologically confirmed cases of tinea on the body and face of patients treated between September 2010 and March 2012 in the Department of Dermatology at the SMG-SNU Boramae Medical Center. The hematoxylin-eosin (H&E)-stained slides of the 18 periodic acid-Schiff stain (PAS)-positive biopsy specimens were reviewed by 2 dermatologists.