What is the recommended diagnostic method for tinea versicolor?

Tinea versicolor, caused by an overgrowth of Malassezia yeast on the skin, is typically diagnosed using a potassium hydroxide (KOH) prep from a skin scraping. This method is preferred because it allows for the visualization of the yeast and hyphae under a microscope after the skin scraping has been treated with KOH, which clears the keratin and makes the fungal elements easier to identify.

While skin biopsy can provide a definitive diagnosis in some dermatological conditions, it is not routinely necessary for tinea versicolor, as the KOH prep usually suffices. Patch testing is used primarily for allergic reactions and contact dermatitis rather than fungal infections, and blood tests do not aid in diagnosing tinea versicolor. The straightforward KOH prep is an effective, quick, and efficient diagnostic method for this specific skin condition.