Figure 5
From: Dermatology for the practicing allergist: Tinea pedis and its complications
KOH preparation of fungal hyphae. This slide shows the branched hyphae of T. rubrum. Scrapings from the outer edge of a tinea lesion should be taken with a sterile scalpel, placed on a slide and KOH applied. KOH dissolves the epithelial cells seen in the background and leaves the fungus to be viewed by microscopy.