Inner thigh stripe erythema is most commonly associated with puberty swelling lines, tinea cruris or eczema. Puberty swelling lines can be controlled by diet and exercise, tinea cruris can be treated by antifungal therapy, and eczema can be treated by anti-inflammatory and anti-allergic therapy. 1. puberty expansion lines: common is the adolescent population, sudden growth and rapid growth of fat and lead to skin collagen fiber damage or fracture and lead to crack-like performance, often purple or yellowish, usually no self-conscious symptoms. Usually pay attention to eat less greasy, eat more vegetables and fruits, strengthen the daily exercise so as to control the rapid growth of weight. 2. Ringworm: caused by fungal infection, ringworm is likely to occur in the unilateral thigh root, and may involve the opposite side or the buttock skin over time. Treatment should be with antifungal drugs, topical drugs such as terbinafine cream, oral drugs such as itraconazole capsules, etc., the therapeutic effect is very good. 3. Eczema: can occur in bilateral femoral, may involve the perianal, scrotal skin, eczema treatment can be weak hormonal ointment such as hydrocortisone butyrate cream, etc., or immunosuppressive ointment such as tacrolimus, pimecrolimus, etc., treatment, severe cases can be combined with oral antihistamines such as chlortetracycline and so on. Erythema striata on the inner thighs may also be caused by other diseases, it is recommended that patients go to the hospital in time, after a clear diagnosis, follow the doctor’s instructions for symptomatic treatment.