A lot of pimples on the back of the head is mainly due to acne, folliculitis, prickly heat, etc. It needs to be treated with physical, applied drugs, oral medication, etc. under the guidance of a doctor. 1. Acne: It is a chronic inflammatory skin disease related to the large amount of sebum secretion, keratinization of follicular sebaceous gland ducts, and propagation of Propionibacterium acnes. It can be treated by topical application of retinoic acid and benzoyl peroxide ointment, oral retinoic acid and other medications, or intense pulsed light. 2. Folliculitis: Folliculitis is mainly caused by bacterial infection. High temperature, excessive sweating, scratching, poor hygiene habits, systemic chronic diseases and other common triggering factors. Attention should be paid to skin hygiene, prevention of trauma and enhancement of immunity. Topical medication is the mainstay of treatment, and mupirocin ointment, fusidic acid cream and other drugs can be applied locally. 3. Prickly heat: prickly heat is caused by hot weather, hot weather will lead to sweat is not easy to evaporate, but also lead to sweat retention, so that the patient appeared in the back of the head a lot of pimples symptoms. You should ventilate the heat, wear loose and breathable clothes, and keep the skin clean and dry. You can apply glycerine lotion, oral antihistamine medication to stop itching treatment. The back of the head a lot of pimples may also be eczema, sebaceous cysts and other causes, need to be under the guidance of the doctor, according to the specific causes of targeted treatment. All of the above drugs should be used under the guidance of a doctor.