The common causes of pimples on the back of the ear include folliculitis, sebaceous cysts and so on, which need to be treated according to the cause of the symptoms, and are usually treated with medication and surgery. 1. Folliculitis: folliculitis caused by bacterial infection. Local topical mupirocin ointment, fusidic acid ointment, etc., while oral antibiotic drugs, such as doxycycline hydrochloride capsules, cefadroxil capsules, etc.. Fungus rarely causes folliculitis behind the ear, except for the folliculitis caused by Malassezia infection in the chest and back area. 2. Sebaceous cysts: Clinical treatment generally adopts the method of surgical excision. All of the above treatments need to be carried out under the guidance of a professional doctor, avoid self-medication. Acne on the back of the ear may also have other causes, it is recommended to go to the hospital in a timely manner to improve the examination, to clarify the cause of the disease to give targeted treatment.