Adult acne stems from the same basic causes as all other acne. Plugged pores result from excess sebum and dead skin cells. However, the external causes may have changed. In adults, acne breakouts often occur due to a change in diet, stress, medication, or cosmetics. When suffering a sudden breakout, check to see what has changed before jumping on the next miracle skin treatment. Even if the problem has been continuous, those factors are worthy of consideration as a change in one or all of them could significantly reduce the severity of the acne problem. However, in the case of an irreversible lifestyle change or continuous acne breakouts, seek an acne treatment that can help you in the long term. Unlike teen acne, adult acne will be there to stay, unless the method used to dispose of it sticks around just as long. Of course, for severe acne contact a dermatologist.