The blackening of pubic hair follicles may be caused by sebaceous cysts or vulvar folliculitis. 1. Sebaceous cysts: patients may not pay attention to cleanliness, resulting in sebaceous cysts, subcutaneous follicles drainage is not smooth, the secretion gathered too much caused by the follicles become black. 2. Vulvar folliculitis: mainly the inflammation caused by the pubic hair follicles, patients do not pay attention to vulvar hygiene, resulting in bacterial infection. Mainly manifested as redness, swelling, itching, pain and other symptoms around the follicular opening, and gradually formed conical pustules, secretions can not be discharged smoothly and mixed with foreign matter follicle blackening. If you have black pubic hair follicles, it is recommended to go to the hospital in time, after clarifying the cause of the disease, under the guidance of a professional physician treatment.