Buns on pubic hair can be caused by folliculitis, boils or sebaceous cysts. 1. Folliculitis: Folliculitis caused by bacterial infection is the most common cause of pimples on pubic hair, which is mainly characterized by localized redness, swelling and pain. 2. Boils: Boils are perifolliculitis, manifested as large inflammatory nodules. If the hair follicles become pus-filled, it can lead to inflammation of the skin follicles, resulting in a pimple on the pubic hair. 3. Sebaceous cysts: Sebaceous glands are not excreted properly, leading to blockage of hair follicles and the formation of cysts, accompanied by inflammation can be accompanied by pain. The hairs of the pubic hairs of the long bag should immediately seek medical attention, under the guidance of the doctor for standardized treatment, do not self-medication in order to avoid delays in the condition.