Acne on the back of the head may be caused by folliculitis, acne, seborrheic dermatitis and other diseases, which can be treated with topical medication, oral medication and physical therapy. 1. Folliculitis: After the skin and hair follicles are damaged, it is easy to cause skin infections, thus causing acne. If it is caused by bacterial infection, you can apply topical fusidic acid cream, mupirocin ointment and other medications, which can play an antibacterial and anti-inflammatory role. If it is caused by fungal infection, you can use topical ketoconazole lotion, clotrimazole cream and other antifungal drugs. 2. Acne: Acne is usually caused by abnormal hormone levels, large amounts of sebum secretion, bacterial infections, etc. It can also cause acne on the back of the head. It can be treated with topical medications such as adapalene gel and fusidic acid cream, and in severe cases, it can also be treated with physical methods such as laser. 3. Seborrheic dermatitis: associated with Malassezia colonization, lipid increase, impaired skin barrier function, immune response and individual susceptibility. It usually occurs on the head and face where the sebaceous glands are exuberant, and will result in acne and itching. Antifungal medications such as ketoconazole compound ointment can be applied, and topical glucocorticoid creams such as mometasone furoate cream can be used. If necessary, drugs such as oral itraconazole capsules and vitamin B2 tablets can be combined. Scalp ringworm can also cause pimples on the back of the head, it is recommended to consult a doctor in a timely manner to clarify the cause of the disease in the doctor’s guidance under standardized treatment. The above medications should be used in accordance with the doctor’s instructions.