Examination for Dermatophytes

Dermatophyte fungi invade the epidermal stratum corneum and the hair. Visualisation of arthrospores in or on the hair is diagnostic of dermatophytosis and is a potentially useful, rapid test.

Plucked hairs and skin scales should be mounted in KOH (or liquid paraffin) and examined microscopically. KOH is preferred by some as it clears the keratin and can make the hyphae and spores more visible. However, it can be difficult to see spores and hyphae by routine light microscopy and the diagnosis must not be discounted if fungi are not seen. Culture is required for further assessment.