Boils on the external auditory canal are caused by acute confined purulent lesions of the skin, which usually occur in the cartilage of the external auditory canal. Boils on the external auditory canal are an undesirable symptom and should be treated as soon as the organism develops them. There are several causes of external auditory canal boils: 1. Injury to the external auditory canal: Usually caused by excessive ear digging. 2. Water accumulation in the external ear canal: This is usually caused by water accumulation in the external ear canal after bathing or swimming, which softens the local epidermis of the external ear canal and causes some bacteria to invade and cause infection. 3. Pathological diseases: For example, the impregnation of pus from purulent otitis media, if the body has some systemic diseases, it may also induce boils in the external ear canal, such as diabetes, endocrine disorders, etc. For the treatment of boils in the external ear canal, an ear bath with antibiotic ear drops can be used in the early stage, together with hot compresses and physical therapy to relieve pain. Once the boil matures, it will break down on its own. Patients who do not break down will need to be incised and drained and then changed regularly to avoid narrowing of the external ear canal. Therefore, once the organism has an external ear canal boil, especially in patients with combined diabetes and autoimmune deficiency, it is important to treat it promptly and identify the cause to avoid further deterioration of the disease.