Pustules growing at the base of the thigh should be considered as boils, sebaceous cysts or lymphadenitis. 1. Boils: mostly caused by Staphylococcus aureus. In summer, the epidermal stratum corneum is impregnated and swollen by sweat, which blocks the mouth of the sweat ducts, and the excretion of sweat is blocked, which is conducive to the propagation of bacteria and easy to form boils. Most of the boils can be ruptured and then heal on their own. In the early stages, before abscesses are formed, ichthyol can be applied locally or antibiotics such as penicillin can be used to fight infection. 2. Sebaceous cysts: Sebaceous cysts are formed when the outer port of the sebaceous gland is blocked, leading to retention of sebum and other sebum, thus forming a cystic swelling, which manifests itself as a subcutaneous swelling, and if the infection is secondary to it, a subcutaneous pustule will be formed. 3. Lymphadenitis: Lymphadenitis and lymphangitis are caused by germs invading the lymphatic system and may occur in various parts of the body. If the above symptoms occur, you should consult a doctor in time to identify the cause and standardize the treatment.