A hard bag on the back of the neck is considered to be folliculitis, sebaceous cyst or lipoma. If folliculitis is recommended to use topical erythromycin ointment, clindamycin ointment anti-inflammatory treatment; sebaceous cysts or lipomas, it is recommended to surgically remove. Folliculitis is due to hair follicle obstruction caused by infection formation of inflammation, manifested as redness, swelling, pain, treatment to anti-inflammatory mainly, commonly used topical anti-inflammatory drugs, erythromycin ointment, clindamycin ointment. If the degree of inflammation is more serious, it is recommended to follow the doctor’s instructions at the same time oral amoxicillin or roxithromycin. Sebaceous cysts are due to the metabolic blockage of sebaceous glands, keratinization of the gland mouth to form cysts with encapsulation. This kind of cyst is not harmful to the body, if it is not obvious, you can not need to treat, if the treatment is recommended to perform surgical resection. Lipoma is a benign subcutaneous tumor, which can grow in any part of the body, generally without special treatment. If it is large enough to compress the surrounding nerves and tissues and cause symptoms, surgery is recommended. It is recommended to consult a dermatologist for targeted treatment under the guidance of a doctor.