Acne Causes and Treatment
Acne is a skin condition in which the pores become blocked, causing pimples to develop. Acne is the most common skin disorder in North America, affecting an estimated 85 percent of adolescents. Effective acne treatments are available to treat existing pimples and prevent new ones from developing. In addition, cosmetic treatments can help to reduce scarring and changes in skin color caused by acne.
How does acne develop ?
There are four basic steps involved in the development of an acne lesion.
- Hair follicles become blocked with an overabundance of normal skin cells (figure 2). These cells combine with sebum (an oily substance that lubricates the hair and skin), creating a plug in the follicle.
- The glands that produce sebum, known as sebaceous glands, enlarge during adolescence and sebum production increases (figure 3). Numerous sebaceous glands are found on the face, neck, chest, upper back, and upper arms.
- The increase in sebum production allows for the overgrowth of bacteria that normally lives on the skin.
- Bacterial overgrowth causes local inflammation, which causes rupture of the follicle (figure 4). This can lead to the formation of a red or tender pimple.
The basic acne lesion is called a comedo. The most common types of pimples are:
- Whiteheads (closed comedones): These pimples are sealed over and have a small white pus filled top.
- Blackheads (open comedones): These pimples have a small, black opening at the top. Although these pimples are black, the color is not from dirt. It’s from the process of oxidation when the sebum is exposed to air.
- Papules: These are tender, small pink bumps.
- Pustules: Pimples that have pus on the top and are red on the bottom of the lesion. These are characteristics of inflammatory acne.
- Nodules: These are hard, large, painful pimples that arise deep in the skin.
- Cysts: Pus-filled, deep, painful pimples that often result in scars.
- Hormonal changes. Hormonal changes during adolescence cause the sebaceous glands to become enlarged and sebum production increases. In most people with acne, hormone levels are normal, but the sebaceous glands are highly sensitive to the hormones. Less often, women’s hormone levels are affected by an underlying medical problem known as polycystic ovary syndrome (PCOS). Acne tends to resolve between ages 30 to 40, although it can persist into or develop for the first time during adulthood. Post-adolescent acne predominantly affects women, in contrast to adolescent acne, which predominantly affects men. Acne can flare before a woman’s menstrual period, especially in women older than 30 years.
- External factors. Oil-based cosmetics may contribute to the development of acne. Oils and greases in hair products can also worsen skin lesions. Water-based or “non-comedogenic” products are less likely to worsen acne. People with acne often use soaps and astringents. While these treatments remove sebum from the skin surface, they do not decrease sebum production; frequent or aggressive scrubbing with these agents can actually worsen acne.
- Diet. The role of diet in acne is controversial. Some studies have found weak associations between cow’s milk and an increased risk of acne, perhaps because of hormones that occur naturally in milk. However, there is no strong evidence that milk, high-fat foods or chocolate increase the risk of acne.
- Stress. Psychological stress can probably worsen acne. In several studies of students, acne severity appeared to worsen during times of increased stress.
- Medicines. Certain medicines, such as those used to treat epilepsy and types of depression.
- Pressure or friction on the skin. Friction caused by backpacks or bike helmets can make acne worse.
- Family history. If other people in your family have acne, there is a greater chance you will have it.
What can you do to reduce acne?
The way you take care of your skin has a big effect on your acne. Here’s what you should do:
- Skin hygiene. Wash your face no more than twice daily using a gentle non-soap facial skin cleanser and warm (not hot) water. Some providers recommend avoiding use of a washcloth or loofah, and instead using the hands to wash the face. Vigorous washing or scrubbing can worsen acne and damage the skin’s surface. Do not pick or squeeze pimples because this may worsen acne and cause skin swelling and scarring. It can also cause lesions to become infected.
- Moisturizers. Use of a moisturizer minimizes dryness and skin peeling, which are common side effects of some acne treatments. Moisturizers that are labeled as “non-comedogenic” are less likely to block skin pores.
- Sun protection. Some acne treatments increase the skin’s sensitivity to sunlight (eg, retinoids, doxycycline). To minimize skin damage from the sun, avoid excessive sun exposure and use a sunscreen with SPF 15 or higher before sun exposure.
- Choose make-up and hair care products that are “non-comedogenic” or “non-acnegenic.” These products have been made in a way that they don’t cause acne. You may also want to use products that are oil-free.
- Avoid things that rub the skin as much as you can, such as backpacks and sports equipment.
- Talk with your doctor about what treatment methods can help your acne. Take your medicines as prescribed. Be sure to tell your doctor if you think medicines you take for other health problems make your acne worse.
Can I treat my own acne?
If you have mild acne, you can try to treat yourself with non-prescription products initially. Non-prescription acne treatments may include salicylic acid, benzoyl peroxide, sulfur, alpha hydroxy acids, or tea tree oil, all of which are available in non- prescription strengths. A combination of these treatments may be more effective than using one single product alone. If you do not improve after three months of using non-prescription products or you have moderate or severe acne, consult a healthcare provider for advice on the most effective treatments.
There is no single best treatment for acne, and combinations of treatments are sometimes recommended. Since acne lesions take at least eight weeks to mature, you should use a treatment for a minimum of two to three months before deciding if the treatment is effective.
Noninflammatory acne causes whiteheads or blackheads without redness or skin swelling .
Retinoids. Topical retinoid medications are often recommended for noninflammatory acne. Examples of these medications include tretinoin, adapalene and tazarotene. Retinoids are usually applied once per day, although people who develop skin irritation can reduce this to every other day or less, then increase as tolerated over time. Most people become more tolerant of retinoids over time. Most retinoids are available in a gel or cream. People with oily skin may prefer gels because they have a drying effect, while people with dry skin may prefer a cream. Retinoids can cause skin irritation. While using topical retinoids, you should apply a sunscreen with SPF 15 or greater before sun exposure.
Other acne products. People who cannot tolerate retinoids may try other topical medications, such as salicylic acid, glycolic acid, or azelaic acid. All of these treatments can be helpful in reducing noninflammatory acne, and azelaic acid may reduce acne-related darkening of skin.
Mild to moderate inflammatory acne
Mild to moderate acne with some inflammation (picture 2) is usually treated with topical retinoids, topical antibiotics, or benzoyl peroxide. A combination of two medications, usually benzoyl peroxide with a topical antibiotic or retinoid (eg, tretinoin), is more effective than treatment with one agent alone.
Moderate to severe inflammatory acne.
For people with moderate to severe inflammatory acne, oral antibiotics or an oral retinoid known as isotretinoin may be recommended. Topical medication may be used in combination with oral treatments. Women often benefit from hormonal treatment with a birth control pill.
Acne and pregnancy
Many acne treatments are not safe for use during pregnancy. Women who are pregnant or intending to become pregnant should consider stopping all acne treatments before becoming pregnant. If acne therapy becomes necessary, discuss the options with your healthcare provider.