KOH prep

A potassium hydroxide (koh) prep is made by sliding some material from the skin, vaginal tract, oral cavity, or some part of the body to see if the cause of the problem is due to fungus (or yeast). Example: candidiasis is a fungal infection of the vagina or oral cavity, often due to side effect of antibiotic therapy, when bacteria die and overgrowth of fungi occurs. Or skin (like athlete's foot).