Though acne is usually the bane of the teenage years, it can linger through the 20s and 30s and possibly longer. Estimates vary, but some dermatologists suggest that at least 80 to 90 percent of the American population has to deal with acne at some time.
Acne can be as slight as a blackhead or as severe as a cyst. While there is no single cause, dermatologists agree that outbreaks may be due to excessive amounts of hormones, bacteria, certain medications, oil-based cosmetics, and foods high in iodides such as seafood, cabbage, peanuts and spinach. In addition, stress can aggravate an acne condition.
Acne is a disease of the skin. The outermost layer of skin is a paper-thin layer of stratum corneum. Next comes the epidermis, a layer of living cells which produces the stratum corneum. The third layer is the dermis, a mass of collagen and fibers with nerves, blood vessels, seat and oil glands, and hair follicles. This is where acne may begin. At the opening of the glands, the cells thicken and form a plug consisting of dead skin, sebum (an oily material) and bacteria. When the plug reaches the skin surface, it is known as a blackhead, or comedo. The blackness is not caused by dirt, but by the pigment melanin. When the plug appears closed, dermatologists call it a whitehead or milia. Generally, sebum clogs the opening and makes it seem closed.
A major cause of acne is hormones whose levels fluctuate during the teenage years and cause changes in the size of oil glands and amount of oil produced. Among the bacteria, a Gram-positive rod named Propionibacterium acnes is often responsible for acne. Ordinarily, this bacillus exists harmlessly in the skin's normal flora, but when there is an overabundant secretion of sebum, it breaks down the excess to fatty acids. The fatty acids, in turn, irritate and aggravate plugs within the pores, thus leading to inflamed pustules, cysts, or red bumps. In addition, the antibodies produced against P. acnes react with bacterial antigens and set off an immune response which leads to further inflammation. Antibiotics such as tetracycline or erythromycin are often prescribed to kill the bacilli, but the drugs may have to be taken for many weeks.
In many cases, acne leaves its mark on the skin with icepick scars or pockmarks, both of which can be successfully removed by local surgery. Dermatologists suggest careful washing with a mild soap to remove excess oils from the skin and frequent shampoos to keep hair oils from reaching the skin. Eating foods rich in vitamin A and avoiding those with iodides may also help prevent or clear acne.
