A hard lump under the skin on the inner thigh accompanied by itching may be due to mosquito bites, epidermal cysts and other factors. Can be relieved by topical medication, oral medication, home care and other ways. 1. Mosquito bites: more mosquitoes in summer, biting to the inner thigh, may cause the patient’s inner thigh subcutaneous redness and swelling nodules, and mosquito bites and local allergic reaction, need to avoid scratching and other further stimulation, through the application of violet dibutylamine, glycerite lotion, etc., to achieve the purpose of cooling and relieving itching. 2. Epidermoid cyst: a benign skin tumor, is a cyst containing keratin in the dermis, manifested as a round elevated skin swelling under the skin, individual may have itching or pain symptoms, if pain can be treated with topical fusidic acid cream, mupirocin ointment, and if necessary, surgical excision can be chosen. Itchy hard lumps under the skin on the inner thighs may also have other causes, need to cooperate with the doctor to check and then do the treatment.