What is acne vulgaris?

Acne vulgaris (acne) is a common skin problem that causes blackheads, whiteheads and other skin lesions. Acne can be found on any part of the skin, but are most commonly found in the face, chest, back, and legs. Acne forms when hair follicles are blocked, which cause an overproduction of sebum (an oily substance) and leads to bacterial growth. The most common bacteria associated with acne is called Propionibacterium acnes (P acnes) and plays a large role in the inflammatory phase of acne. The most severe cases of acne are inflammatory, which is characterized by pus-filled nodules that tend to form the worst acne scars.

Although hormones can play an important role in the formation of acne, most patients have normal hormone levels. Age also plays a role in acne prevalence, which usually resolves by itself with age. Diet is a controversial cause of acne and there is no evidence that a high fat or sugar diet causes acne.