Eczema on the buttocks and ringworm are different in terms of etiology, skin damage characteristics, laboratory tests and so on. 1. Etiology: eczema is an itchy and allergic inflammatory reaction of the skin caused by a variety of internal and external factors, which may be related to mental stress, overwork, irregular diet, local sweating or allergy. Ringworm is caused by Trichophyton rubrum, Trichophyton mustelii or other fungal infections. It is a fungal infectious disease that occurs on the vulva, scrotum, thighs or perianal area. 2. Characteristics of skin damage: Skin damage of eczema can occur in thighs, vulva or perianal area. Skin damage is mainly erythema and herpetic papules, even oozing and crusting, recurring and accompanied by severe itching. The skin damage of tinea cruris is basically erythema on the thighs, scrotum, vulva or perianal area, with flaky surface, and common ring-like erythema at the edge of activity, which can be diagnosed by mycological examination. 3. Laboratory examination: the blood routine of eczema is generally characterized by eosinophilia, without fungal infection. Ringworm can be diagnosed by fungal culture and microscopy to identify the type of fungus. When the above diseases occur, it is recommended to consult a doctor in time for further examination, to clarify the cause under the guidance of the doctor, and to carry out targeted treatment or therapy.