How are superficial fungal infections diagnosed?

Superficial fungal infections can usually be suspected clinically, but definitive diagnosis requires the demonstration of fungal pathogens by microscopic examination or culture of skin, nail, or hair scrapings from the suspected lesion. During microscopic examination, hyphae are sought in the material. The material is first placed on a glass slide, and then 1 or 2 drops of 10% to 20% potassium hydroxide (KOH) are added. A fungal stain such as chlorazol black E may be added to the preparation to aid visualization of the fungal elements. The hyphae of dermatophytes will be septate and typically demonstrate branching. Skin scrapings can also be placed on culture media. Culturing the organism, in addition to being a diagnostic aid, permits speciation of the organism.