In most cases, your doctor can diagnose (tinea pedis) by looking at your foot. He or she will also ask about your symptoms and any previous you have had.
If your symptoms look unusual or if a previous infection has not responded well to treatment, your doctor may collect a skin or nail sample by lightly scratching the skin with a blade or the edge of a microscope slide, or by trimming a nail. He or she will examine the skin and nail samples using laboratory tests including:
In rare cases, a skin biopsy will be done by removing a small piece of skin that will be looked at under a microscope.