A constant bump on the head may be folliculitis of the scalp, or purulent inflammation of the hair follicles, most commonly due to bacterial infection, manifested as follicular inflammatory papules and pustules, which can be accompanied by local redness, swelling, heat and pain. Some patients are prone to recurrent folliculitis on the head, which may be related to genetic background, oily skin type, environmental factors, and personal hygiene habits. There are more sebaceous glands on the head, and the sebaceous glands secrete a lot, and lack of hygiene and frequent scratching can cause local infection. Young men are more likely to have recurrent folliculitis on the head due to androgen secretion. There are also some patients who are prone to recurrent folliculitis due to decreased resistance, such as diabetics.