A pimple on the root of the thigh may be folliculitis, suppurative sweating or infectious molluscum contagiosum, etc. The treatment includes medication, surgery, etc., and the patient should follow the doctor’s instructions for treatment. 1. Folliculitis: Folliculitis is a purulent skin disease that occurs in and around hair follicles. If there is purulent material on the top of the large acne on the thigh root, and it is accompanied by redness, swelling and pain, it is considered to be folliculitis caused by bacterial infection. Patients can follow the doctor’s instructions to use erythromycin ointment, mupirocin ointment and other drugs for treatment. 2. suppurative sweating: the disease is a kind of chronic recurrent inflammatory skin disease due to the follicle atresia leading to the involvement of follicle sebaceous gland unit. If the patient is fat, repeated friction of the skin in the thigh root area of the legs, or prolonged sweat stimulation, etc., it may induce suppurative sweating inflammation, like a big pimple. Patients can be given antibiotics, intradermal injection of betamethasone and other drugs according to the condition as prescribed by the doctor. Oral vitamin A drugs, ampicillin and other treatments. 3. Molluscum contagiosum: Molluscum contagiosum is a poxvirus infection caused by the molluscum contagiosum virus, and human beings are the only natural hosts of this virus. If the patient has a recent history of wild swimming, sex, and thigh root of the large acne without obvious itching, more brown, flesh-colored, etc., may be infectious molluscum contagiosum. Patients can follow the doctor’s instructions to use retinoic acid ointment, imiquimod cream and other drugs for drug treatment. If necessary, you can consider the warts clip removal surgery and other physical treatment methods. If you feel unwell, you should go to the hospital in time, so as not to delay the condition or cause adverse reactions.