Consider the possibility of eczema, ringworm, and folliculitis. The area is moist and sweaty and prone to eczema and ringworm, both of which present as flaky erythematous patches with itching and are easily misdiagnosed. However, the causes of the two are completely different, with eczema being an allergic disease and ringworm being a fungal infection. Eczema does not respond to medications used to treat ringworm, but ringworm has a good effect on medications used to treat eczema initially, which rebound and intensify after discontinuation. Therefore, it is especially important to diagnose it correctly and not to use medication indiscriminately. Tinea cruris is longer, up to several months or even years, round or oval with clearer borders, darker edges and lighter central color, with a tendency to expand in a circle and small blisters or scales around the edges. Eczema has fuzzier borders and no central pale manifestation. The two can be identified by dander fungal direct examination: that is, scrape some of the affected area with a scraper dander, magnified with a light microscope to see. Fungal preferred ointments such as Butenafine and Miconazole. Eczema preferred ointments such as Fuyanin and Eloson. Medication is used for 2-4 weeks. Folliculitis is mostly isolated small bumps that may have a tendency to fuse, are not accompanied by itching, may be painful, and may have yellow or purulent discharge on the surface. The occurrence of the above diseases are related to local humidity and lack of ventilation. Pay attention to wearing less jeans and more pants with good ventilation, pay attention to personal hygiene and boil and scald more intimate clothing.