A bulge behind the ear hole may be caused by boils, keloids, sebaceous cysts, etc. Boils can be treated with mupirocin ointment, keloids can be treated with X-ray radiation, and sebaceous cysts can be treated with cystectomy. 1. Boils: A bulge behind the ear hole may be due to localized infection, accompanied by redness, swelling and pain, which can be relieved by applying mupirocin ointment in appropriate amounts. 2. Keloid: a benign skin tumor caused by excessive proliferation of connective tissue in the skin, can be seen in the neck, shoulder, ear and other parts of the prevention of trauma and infection can prevent the occurrence of keloid, early lesions can be selected X-ray radiation therapy, glucocorticoid lesions within the point of injection is also effective, generally do not advocate surgical excision. 3. sebaceous cysts: the main symptom for the local subcutaneous spherical cystic swelling, clear boundaries, protruding from the surface of the skin, no infection is recommended for surgical excision, such as cyst excision surgery, there is abscess formation, need to be excised and drained, postoperative to maintain cleanliness and hygiene, avoiding water. When found behind the ear hole bulging a bag, it is recommended to seek medical advice to identify the cause of the disease, under the guidance of a professional doctor targeted treatment. The above drugs need to be used in accordance with medical advice.