Millions of Americans are plagued by acne. Although there is no cure, it is a very treatable condition. Acne treatment is highly personalized, and you will have to work with your dermatologist to develop an individualized treatment plan. Below is some basic information which will help you to better understand what causes acne and how it may be treated.
First, it is important to address some myths about acne:
(1) Fatty foods and chocolate have not been linked to acne, but a few studies have shown an association between dairy and acne.
(2) Acne is not a result of poor hygiene. Dirt does not cause acne and compulsive face washing will not ameliorate it. In fact, too-frequent washing may cause irritation that can worsen the appearance of acne.
(3) Stress does not cause acne, although it may cause you to pick at your lesions more than usual.
(4) Acne can occur beyond your teenage years. Many people in their 30s and 40s have acne.
(5) Acne is more than a cosmetic concern. Acne can have a profound effect on confidence and self-esteem. In addition, severe cases of acne can lead to irreversible scarring.
So what actually causes acne? It turns out that a number of factors play a role.
First, your face, chest, and back contain hair follicles. Within these follicles are sebaceous glands. These glands release sebum, or oil, which exits via the pores of your skin. Acne occurs when these pores become blocked, as can happen during the continuous renewal of skin cells. As oil and bacteria accumulate within the blocked follicle, the acne lesion grows.
Second, androgens, a hormonal subtype, cause sebaceous glands to grow larger and release more oil. The role of androgens in the evolution of acne lesions can be observed by the development of acne during puberty and acne flares during menstruation, two examples of increased hormone production.
Finally, Propionibacterium acnes is a bacteria that naturally resides on your skin. When the hair follicle becomes plugged, these bacteria multiply much faster than usual, and an overgrowth occurs. Bacterial overgrowth stimulates the immune system to protect the body, which leads to the redness and pus associated with inflammation.
Blocked follicles plus large and overactive sebaceous glands plus bacterial overgrowth lead to the following progression of acne lesions:
- Microcomedones – this is one way of describing a clogged pore. It is the initial acne lesion and not visibly appreciated.
- Comedones – this is the first visible, non-inflamed acne lesion. It has two forms:
- Closed comedones or whiteheads – As the name implies, the sebum and bacteria remain trapped underneath the skin
- Open comedones or blackheads – These are open pores, consisting of keratin (a type of protein that makes up the skin), sebum, and bacteria. The black pigment is oxidized sebum, not dirt!
- Papules – This is the first inflammatory lesion in the acne cascade. A break in the follicle’s wall leads to the leakage of bacteria into the surrounding environment, leading to infection and causing a red, inflamed lesion. This is why you should not pick at your whiteheads: if you rupture the follicle roof yourself, you are essentially asking for infection and inflammation, and your unassuming comedone will almost automatically transform itself into an inflamed pimple.
- Pustules – Inflammation is the immune system’s response to the clogged pore, bacterial proliferation, and infection. The pus that you see is the accumulation of white blood cells, which have been sent by the immune system to fight infection.
- Nodules and cysts – Compromised follicular walls and leakage of sebum and bacteria into the surrounding skin lead to the spread of infection. Nodules and cysts are the most concerning skin lesions because they can lead to significant disfigurement and permanent scarring.
Different lesions and phases of acne progression call for different treatment. If you are interested in learning more about how to treat acne, please visit the second installment of this article.
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Marks JG, Miller JJ. Pustules. In: Lookingbill & Marks’ Principles of Dermatology. 4th ed. Elsevier Inc; 2006:171-176.
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Wolff K, Johnson RA, “Section 1. Disorders of Sebaceous and Apocrine Glands” (Chapter). Wolff K, Johnson RA: Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, 6e: http://www.accessmedicine.com/content.aspx?aID=5185601.