A white pustule on the leg may be caused by folliculitis, epidermal cysts and other diseases, the patient should consult a doctor in a timely manner to clarify the cause of treatment. 1. Folliculitis: a white pustule on the leg may be the local hair follicles occurring purulent inflammation caused by the patient will also have local redness, swelling, pain, can be used externally metronidazole, mupirocin cream and other drugs for treatment. 2. Epidermoid cysts: Epidermoid cysts usually have no obvious symptoms, and after pressure or secondary infection, they may become pus, break out, redness, swelling and pain. All of the above medications and treatments should be administered under the guidance of a physician.