Genetics is thought to be the primary cause of acne in 80% of cases.[2] The role of diet and cigarette smoking is unclear, and neither cleanliness nor exposure to sunlight appear to play a part.[2][13][14] In both sexes, hormones called androgens appear to be part of the underlying mechanism, by causing increased production of sebum.[5] Another frequent factor is excessive growth of the bacterium Cutibacterium acnes, which is normally present on the skin.[15]
^ Jump up to: a b GBD 2015 Disease and Injury Incidence and Prevalence, Collaborators. (8 October 2016). "Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1545–1602. doi:10.1016/S0140-6736(16)31678-6. PMC 5055577. PMID 27733282.
Many different treatments exist for acne. These include alpha hydroxy acid, anti-androgen medications, antibiotics, antiseborrheic medications, azelaic acid, benzoyl peroxide, hormonal treatments, keratolytic soaps, nicotinamide, retinoids, and salicylic acid.[75] They are believed to work in at least four different ways, including the following: reducing inflammation, hormonal manipulation, killing P. acnes, and normalizing skin cell shedding and sebum production in the pore to prevent blockage.[76] Common treatments include topical therapies such as antibiotics, benzoyl peroxide, and retinoids, and systemic therapies including antibiotics, hormonal agents, and oral retinoids.[20][77]
Temporary skin fillers have been used for years for acne scar treatment, but a permanent dermal filler was approved for use by the FDA only recently. Designed to remove moderate to severe acne scarring, Bellafill is made up of 80 percent collagen to replace lost volume and 20 percent polymethylmethacrylate, which helps your body heal by boosting protein production.
The verdict on smoking and its relationship to acne is still undecided. The evidence goes back and forth; while many studies seem to prove this theory, other studies contradict such research. For example, research published in 2001 by the British Journal of Dermatology concluded that out of 896 participants, smokers tended to have more acne in general; the more they smoked, the worse their acne felt and appeared. Confusingly, a study published just five years later in the Journal of Investigative Dermatology offered opposing research; nurses interviewed over 27,000 men within a span of 20 years and found that active smokers showed significantly lower severe than non-smokers. Although smoking’s relationship with acne vulgaris is undetermined, smoking has proven effects on acne inversa. It also disrupts hormonal balance, lowers vitamin E levels (an essential antioxidant in skin), induces higher instances of psoriasis, decreases oxygen flow to skin cells, and slows the healing process of open sores. Acne aside, smoking promotes wrinkles and premature aging. Did we mention it’s also deadly? Kick this habit to the curb; your skin will thank you.

Acne appears when a pore in our skin clogs. This clog begins with dead skin cells. Normally, dead skin cells rise to surface of the pore, and the body sheds the cells. When the body starts to make lots of sebum (see-bum), oil that keeps our skin from drying out, the dead skin cells can stick together inside the pore. Instead of rising to the surface, the cells become trapped inside the pore.