The main causes of ear acne are as follows. First, the skin follicles of the external auditory canal, or outer ear, have a reduced ability to purify themselves. The external ear canal has secretions from the cerumen gland, which has an antibacterial effect. Patients who often have acne in the external ear canal combined with otitis externa are those whose cerumen gland secretion is abnormal, either moist or hypersecretory. Patients can also be seen to frequently pull out their ears, and the skin of the ear is more red or even smoother, which are abnormal skin conditions. Second, the patient may have other factors, such as having diabetes, and can use other immunosuppressive drugs, such as glucocorticoids and other anti-tumor drugs, which can suppress the patient’s immunity and make the patient’s physique decline. Clinical treatment is mainly anti-infective treatment, and the second one is to actively treat the inflammation of the external tract.