Adult acne is a form of common acne that can occur to people over 30 years of age. It is not uncommon for people who had no acne as a young person to found that they are having breakouts. Acne appearance in an adult could have a number of causes. The following are seven causes of adult acne: 1. Frequently the acne that one had as a teenager resurfaces later in adulthood. It is not always obvious why this occurs, but it is one reason for acne presence in adults. 2. In women, acne often reappears during pregnancy. This could also be true in the case of women during their menstrual period. 3. Something unusual is going on. It is smart idea to talk to a dermatologist or your family physician. More possible causes of adult acne: 4. Particular medications can provoke acne. These medications include anabolic steroids, lithium, anti-tuberculosis drugs rifampin and isoniazid, anti-epileptic drugs and medications that contain iodine. 5. Constant physical pressure on the skin. Whether wearing a helmet or carrying a backpack, such pressure against the skin can cause breakouts. 6. Chlorinated industrial chemicals are another possible cause. Working in particular types of industrial environments can cause acne-like symptoms or even chloracne - a job-related skin disorder caused by constant exposure to chemicals, such as chlorinated dioxins. 7. Metabolic changes are yet another cause of adult acne. With changes in the hormonal balance of the body, such as those present during menstruation or pregnancy can cause acne in adults.