We do know that the sebaceous glands secrete an oil that changes to a solid white substance called sebum. This travels to the opening of a hair follicle and erupts on the skins surface. This process may be due to an infection of these glands or to excessive amounts of male hormones call androgens.
Blackheads appear when sebum mixes with skin pigments in plugged pores.
They are a mixture of sebum and skin scales that have closed off a hair follicle. Since the exact source of acne is not known, it is often difficult to determine a treatment that will work. Wash your skin twice a day with warm water and a gentle pH balanced soap that does not contain sulfur, chemicals, or perfume. Steam your face a few times a week to open and cleanse your pores. Boil some water in a pot on the stove, turn off the heat, cover your head and face with a towel and hang your face over the pot.