- What causes this disorder?
Acne, which is seen in nearly all teenagers and young adults to some degree, results from increased sebum production in sebaceous glands after puberty with the increase in androgenous steroids. Sebum and keratinaceous debris block hair follicles, leading to comedone formation. Bacteria in the comedones, such as the organism Propionibacterium acnes, cause inflammation and enlargement to form a pustule or nodule. This can rupture to produce a cystic area, generally a lesion >0.5 cm, in which the purulent lesion extends with inflammation into the surrounding dermis.
- What is the course of this disease?
It is self-limited and generally abates in young adulthood. Males are affected more than females, though persistence of acne may be longer in women. A small subset of patients develop the lesion seen in this image. The result of severe acne can be scarring, more likely in males. About 10 to 20% of adults may manifest acne.
- What is the role of hygiene and diet?
Washing with soap or use of other cleansers has a minimal effect. Avoidance of cosmetics that clog pores will help. Diet has minimal effect.
- What therapies are available?
Manual extraction of comedones can help considerably. Topical keratolytic agents that reducing pore plugging include retinoids (vitamin A acids and their synthetic analogs), azelaic acid, and the alpha-hydroxy acids (AHAs). Retinoids increase follicular epithelial cell turnover and shedding of keratinocytes. Azelaic acid reduces follicular hyperkeratosis and has antibacterial properties. The AHAs facilitate stratum corneum desquamation.
Antibacterial agents include benzoyl peroxide, topical antibiotics, and systemic antibiotics. Benzoyl peroxide helps diminish growth of P. acnes. The most common topical antibiotics are clindamycin and erythromycin. Systemic antibiotics are considered in moderate to severe cases of acne with a potential for scarring, and the agents used include tetracycline, minocycline, doxycycline, erythromycin, and azithromycin. In women, oral contraceptives can help alleviate acne. In severe cases resistant to other therapies, use of isotretinoin is considered. Isotretinoin markedly reduces sebum production and increases desquamation of keratinocytes, but at the expense of adverse effects in all cases, including development of dry, fragile skin and eczema, as well as teratogenic effects requiring avoidance of pregnancy.
