The cause of head acne is related to the nature of the acne. Consider folliculitis, acne, ringworm of the head, etc. for head acne. 1. Folliculitis: When the skin or hair follicles of the body are damaged, bacteria will enter the interior of the skin to multiply, and the hair follicles will be infected to trigger folliculitis. 2. Acne: The cause of acne is related to high androgen levels and increased sebum secretion. It is common in adolescents, as a result of increased androgen levels, sebum is secreted in large quantities, resulting in the inability to discharge sebum, which can cause the over proliferation of Propionibacterium acnes and the emergence of acne. 3. Ringworm of the head: ringworm of the head is a fungal infection, fungal invasion of the scalp will cause skin lesions, according to the germs and clinical manifestations, can be divided into yellow ringworm, white ringworm, black spot ringworm and pustular ringworm, which pustular ringworm manifested as dense inflammatory follicular papules and small pustules, looks like a pimple. Pimples on the head, it is recommended to go to the hospital for a detailed examination and symptomatic treatment for the cause.