Sweat patches, also known as lichen planus, are difficult to cure and often recur. It is a chronic fungal disease of the superficial stratum corneum of the skin, caused by Malassezia furfur infection. Malassezia belongs to the normal flora of the human body, and only under some special circumstances will it multiply and cause disease, such as excessive skin sweating, diabetic patients or relatively high external temperature and humidity, which all help Malassezia to cause disease. Treatment is mainly to remove the triggering factors, the larger area can be oral antifungal drugs, such as ketoconazole 400mg, eat once every half month, for 2 times; local can be topical ketoconazole shampoo bath, once every 3 days, first wash the whole body with shampoo, then ketoconazole shampoo applied to the body, stay for 5 minutes, rinse off with water. If frequent attacks, you can also intermittently and repeatedly apply antifungal drugs, such as fluconazole 0.15g orally, once a month.