Comparative study for the reliability of cellophane tape and standard KOH mount in diagnosis of pityriasis versicolor

The Gulf Journal of Dermatology and Venereology ABSTRACT Pityriasis versicolor (PV), a mycotic infection, is characterized by discrete or concrescent, scaly, discolored or hypopigmented areas. The clinical presentation, though very typical, may be confused with other skin disorders. This study was aimed to evaluate the reliability of cellophane tape as a method for diagnosis of PV versus the standard KOH method. Fifty patients suffering from PV were included. Every patient was subjected to scraping of lesions with a blunt scalpel, and then a drop of 10% KOH solution was added. Another sample was obtained using adhesive cellophane tape applied over the affected site, then stucked on the surface of a glass slide after placing a drop of 10% KOH. Both samples were then examined for fungus under microscope. The cellophane tape method was positive in 49 cases out of 50 (98%) while the KOH mount was positive in 48 cases (96%). Fungal elements were detected by both methods and were better visualized by the tape method. All negative cases were of hypopigmented type. Similar reliability was observed with the two procedures as there was no significant difference between results of both cellophane tape and standard KOH methods.