There are many reasons for ear acne, such as folliculitis and sebaceous cysts. 1. Folliculitis: If the ear follicle is infected by bacteria, it will trigger an inflammatory reaction, which can cause the phenomenon of ear acne, accompanied by redness, swelling and pain. 2. Sebaceous cysts: the ear has sebaceous gland distribution, if the sebaceous gland discharge is blocked, can cause sebaceous gland blockage, thus forming cysts, resulting in the phenomenon of ear acne. There are many reasons for ear acne, it is recommended that timely medical treatment, not to ignore the symptoms, take it lightly, so as not to delay the treatment of the condition.