Which of the following is a skin condition?
Acne, also known as "acne vulgaris", is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and possible scarring. It primarily affects skin with a relatively high number of oil glands, including the face, upper part of the chest, and back.
Susceptibility to acne is primarily genetic in 80% of cases. The role of diet and cigarette smoking in the condition is unclear, and neither cleanliness nor exposure to sunlight appears to play a part. In both sexes, hormones called androgens appear to be part of the underlying mechanism, by causing increased production of sebum. Another common factor is the excessive growth of the bacterium 'Cutibacterium acnes', which is present on the skin.
Treatments for acne are available, including lifestyle changes, medications, and medical procedures. Eating fewer simple carbohydrates such as sugar may minimize the condition. Treatments applied directly to the affected skin, such as azelaic acid, benzoyl peroxide, and salicylic acid, are commonly used. Antibiotics and retinoids are available in formulations that are applied to the skin and taken by mouth for the treatment of acne.
In 2015, acne affected approximately 633 million people globally, making it the eighth-most common disease worldwide.