Acne

Acne vulgaris, more commonly known as Acne, is a common skin condition affecting 35-90% of adolescents, and may persist into adulthood in some cases^1,3,4.  Onset commonly commences during puberty, and it may be hormonally influenced through various other stages of life such as pregnancy and menopause^1,3,4. Acne may lead to the development of a low self-esteem and social withdrawal due to its physical appearance¹.

Acne is a chronic inflammatory skin concern that affects the pilosebaceous unit, which is the area of the skin that includes the hair follicle and sebaceous (oil) gland.  Acne may vary in severity from mild to severe^2,3,4,5,6.  There are four factors which have been identified to play a major role in the development of acne and these include:

• Hyperkeratinisation: this is the excess production of skin cells, and this factor is heavily involved in the development of acne lesions^2,4,6
• Increased sebum production: this factor leads to the development of oily skin and is controlled by hormones called androgens such as testosterone and dihydrotestosterone^1,2,4,5,6
• Bacterial involvement: Propionibacterium acnes is the bacteria implicated in the development of inflammatory acne. This bacteria is naturally found on the skin, however in some cases of acne it can grow into excess.  It is involved in the development of inflammatory acne lesions such as papules, pustules and cysts^1,2,4,6
• Inflammation: this factor can cause the swelling, redness and pain experiencd with acne lesions^1,2,4,6

Although the above four factors have been identified to play a major role, the cause of acne is multifactorial, meaning that there are a range of factors, both internal and external, that may contribute to its presence^1,4,6. These may include the following:

Acne lesions commonly described as ‘blackheads’ and ‘whiteheads’ are of concern to sufferers of the condition. They develop due to excess skin cells and sebum collecting within the pilosebaceous unit^2,4,6 The combination of the excess production of skin cells and sebum reduces the ability of skin cells to be removed from the skin via shedding as in normal situations in the process called desquammation, hence the pilosebaceous unit becomes blocked leading to the formation of acne lesions^4,6.

Microcomedones are the initial lesion formed and are invisible to the naked eye. As the pilosebaceous unit becomes further congested with dead skin cells and sebum, it enlarges and the acne lesion becomes bigger forming open and closed comedones which are visible^2,4.  If the lesion becomes colonised by the Propionibacterium acnes bacteria, inflammatory lesions such as papules and pustules may result^2,4.  The presence of these lesions tend to be accompanied by redness, swelling and on occasion pain⁴. If inflammatory lesions are not managed effectively, they may result in the development of pitted acne scars and hyperpigmentation within the affected area².

As acne affects the pilosebaceous unit, the lesions present in areas where there is a higher density of these units such as the face, neck, upper chest, back and shoulders^2,3,4.   Acne may present with both inflammatory and non-inflammatory skin lesions including the following⁵:

^2,3,4,5

People suffering from acne may also experience oily skin, inflammation, redness, sensitivity, reactivity to products, hyperpigmentation and pitted scarring^2,3.

Treatment of acne can be challenging due to there being so many potential influences on its development, however addressing symptoms such as the reduction of acne lesions and oily skin followed by ongoing maintenance can be successful in reducing the appearance of the condition while reducing the incidence of scarring and hyperpigmentation^2,3.

For treatment to be successful, it needs to be able to address as many of the causative factors as possible such as assisting the removal of excess skin cells through exfoliation, reducing sebum and inflammation and addressing the influence of Propionibacterium acnes if implicated^2,3.  It is also important to assess the severity of the condition, the skin type and the symptoms present to determine the most appropriate treatment intervention^2,3.

¹ Bhat, Y. J., Latief, I., & Hassan, I. (2017). Update on the etiopathogenesis and treatment of acne. Indian Journal of Dermatology, Venereology and Leprology, 83(3), 298-306. doi: 10.4103/0378-6323.199581

² Das, S., & Reynolds, R. V. (2014). Recent advances in acne pathogenesis: implications for therapy. American Journal of Clinical Dermatology, 15(6), 479-488. doi: 10.1007/s40257-014-0099-z

³ Gold, M.H., Baldwin, H., & Lin, T. (2017). Management of comedonal acne vulgaris with fixed-combination topical therapy. Journal of Cosmetic Dermatology, 17(2), 227-231. doi: 10.1111/jocd.12497

⁴ Gollnick, H. P. M. (2015). From new findings in acne pathogenesis to new approaches in treatment. Journal of the European Academy of Dermatology and Venereology, 29(Supp 5), 1-7. doi: 10.1111/jdv.13186

⁵ Li, X., He, C., Chen, Z., Zhou, C., Gan, Y., & Jia, Y. (2017). A review of the role of sebum in the mechanism of acne pathogenesis. Journal of Cosmetic Dermatology, 16(2), 168-173. doi: 10.1111/jocd.12345

⁶ Manfredini, M., Mazzaglia, G., Ciardo, S., Farnetani, F., Mandel, V. D., Longo, C., Zauli, S., Bettoli, V., Virgili, A., Pellacani, G. (2015). Acne: in vivo morphologic study of lesions and surrounding skin by means of reflectance confocalmicroscopy. Journal of the European Academy of Dermatology and Venereology, 29(5), 933-939. doi: 10.1111/jdv.12730