The cause of long tinea cruris may be related to dermatophyte infection, and tinea cruris may be induced in people with moist hands and high activity; the cause of long tinea pedis may be related to pathogenic bacterial infection, and tinea cruris may be induced by hot and humid environments and impaired immune function. 1. Ringworm: (1) dermatophyte infection: including Trichophyton spp, Microsporum spp, and Epidermophyton spp. If infecting the skin of the hands, it may lead to the appearance of tinea cruris. (2) Damp hands: If the hands are in a damp state for a long time, it may be easier to induce tinea cruris. (3) People with a lot of activity: If there is a lot of activity, it may trigger localized sweating, which may induce tinea cruris. 2. Tinea pedis: (1) Pathogenic bacteria infection: common pathogenic bacteria include Trichophyton rubrum, Trichophyton mustelii, etc. If the skin of the foot is infected by the above pathogenic bacteria, tinea pedis will easily appear. (2) Hot and humid environment: If the feet are in hot and humid environment for a long time, such as sweaty feet, breathable shoes, etc., tinea pedis may be induced or aggravated. (3) impaired immune function: diabetes, AIDS and other patients with impaired immune function, their own resistance may be reduced, the body may be susceptible to germs invasion, the chances of tinea pedis will increase. There are many reasons for ringworm and tinea pedis, in addition, ringworm and tinea pedis are both contagious, if you suffer from one of these diseases, you may be infected other parts of the body through contact. It is recommended that patients consult a doctor about this.