What method is used to diagnose tinea versicolor besides physical examination?

Tinea versicolor is a common fungal condition caused by an overgrowth of Malassezia yeast on the skin. While physical examination can often lead to a clinical diagnosis, the KOH prep from skin scraping is an important diagnostic technique that allows for confirmation of the diagnosis.

By obtaining a skin scraping from the affected area and applying a potassium hydroxide (KOH) solution, the clinician can dissolve the keratin and other cellular material, which makes it easier to visualize the fungal elements under a microscope. The presence of hyphae and spores ("spaghetti and meatballs" appearance) confirms the diagnosis of tinea versicolor. This method is particularly useful because it can help distinguish tinea versicolor from other dermatological conditions that may have similar presentations, such as vitiligo or seborrheic dermatitis.

While the other methods listed can also be useful in the diagnosis of various skin conditions, KOH prep remains a simple, quick, and effective test for confirming tinea versicolor specifically. For example, Woods lamp fluorescence can sometimes aid in the diagnosis as the affected skin may show a yellow-green fluorescence due to the presence of the organism, but this is not as definitive as the KOH prep. Skin biopsy and culture of skin samples are