Most of the reasons for acne on the neck are folliculitis. The sebaceous glands of the mandible joint and neck are secreted vigorously, which is easy to produce oil, so it is easy to block the hair follicles, which leads to acne. At this time, you should go to the hospital and apply some Dragon Ball Ointment or western medicine erythromycin Ointment. Secondly, the acne at the neck is also related to wearing a necklace, or rubbing the collar of the clothes, and abusing cosmetics, which causes allergy or infection at the neck, redness, itching, and acne. At this time, it is necessary to treat the symptoms, and distinguish between allergy and friction inflammation. In addition, check the thyroid or other parts of the neck to prevent other diseases.