Mimickers of dermatophytes on KOH mount

Abstract

The dermatophytes are a group of filamentous fungi that infect only superficial keratinized tissues of skin, hair and nails. KOH mount is an easy and rapid method to detect them. It is generally not difficult to make a diagnosis of dermatophytes on KOH based on typical characteristic appearance. However, sometimes the diagnosis becomes a challenge because of numerous normal structures which can be very similar to dermatophytes, especially when scrapings are taken from already treated modified tinea infection. This may lead to an erroneous diagnosis and inappropriate treatment of the patient with antifungal drugs which have their own side effects. In the present article, numerous mimickers of dermatophytes on KOH are described with the purpose of avoiding the potential diagnostic pitfalls.