Benzoyl peroxide attacks the P. acnes bacteria. However, one of its main side effects is dryness: If you’re going to use anything with benzoyl peroxide, make sure to moisturize afterwards. Sulfur and azelaic acid are less common and less severe alternatives to benzoyl peroxide. Dr. Peter Lio, assistant professor of clinical dermatology at Northwestern University, says sulfur-based treatments are “a good fit for patients who can’t tolerate the side effects of benzoyl peroxide.”
Pimples are raised red spots with a white center that develop when blocked hair follicles become inflamed or infected with bacteria. Blockages and inflammation that develop deep inside hair follicles produce cystlike lumps beneath the surface of your skin. Other pores in your skin, which are the openings of the sweat glands, aren't usually involved in acne.