Ear acne may be caused by folliculitis, acne, sebaceous cysts and other factors. 1. Folliculitis: The skin sweats more, which easily induces bacterial infection, and the bacteria invade the hair follicles leading to inflammation. If it occurs in the ear, it leads to localized acne and is usually accompanied by redness, swelling, heat and pain. 2. Acne: The sebum secretion in the ear is more vigorous, sebum proliferation, hair follicle blockage, Propionibacterium acnes value-added, resulting in localized pimples. 3. Sebaceous cysts: the sebum secreted by the sebaceous glands in the ear can not be normally discharged from the mouth of the hair follicle, and collects locally to form cysts, resulting in localized acne. In addition to this, mosquito bites, frostbite can also lead to ear acne. It is recommended to consult the dermatology department of the hospital, analyze the cause of the disease according to the results of the examination, and follow the doctor’s instructions for treatment.