Acne is a chronic, inflammatory skin condition that causes spots and pimples, especially on the face, shoulders, back, neck, chest, and upper arms.
It is the most common skin condition in the United States, affecting up to 50 million Americans yearly.
It commonly occurs during puberty, when the sebaceous glands activate, but it can occur at any age. It is not dangerous, but it can leave skin scars.
The glands produce oil and are stimulated by male hormones produced by the adrenal glands in both males and females.
At least 85 percent of people in the U.S. experience acne between the ages of 12 and 24 years.
Fast facts on acne
Here are some facts about acne. More detail is in the main article.
- Acne is a skin disease involving the oil glands at the base of hair follicles.
- It affects 3 in every 4 people aged 11 to 30 years.
- It is not dangerous, but it can leave skin scars.
- Treatment depends on how severe and persistent it is.
- Risk factors include genetics, the menstrual cycle, anxiety and stress, hot and humid climates, using oil-based makeup, and squeezing pimples.
There are many suggested home remedies for acne, but not all of them are supported by research.
Diet: It is unclear what role diet plays in worsening acne. Scientists have found that people who consume a diet that offers a good supply of vitamins A and E and of zinc may have a lower risk of severe acne. One review describes the link between acne and diet as "controversial," but suggests that a diet with a low glycemic load may help.
Tea-tree oil: Results of a study of 60 patients published in the Indian Journal of Dermatology, Venereology, and Leprology suggested that 5-percent tea-tree oil may help treat mild to moderate acne.
If you want to buy tea-tree oil, then there is an excellent selection online with thousands of customer reviews.
Tea: There is some evidence that polyphenols from tea, including green tea, applied in a topical preparation, may be beneficial in reducing sebum production and treating acne. However, the compounds in this case were extracted from tea, rather than using tea directly.
Moisturizers: These can soothe the skin, especially in people who are using acne treatment such as isotretinoin, say researchers. Moisturizers containing aloe vera at a concentration of at least 10 percent or witch hazel can have a soothing and possibly anti-inflammatory effect.
Human skin has pores that connect to oil glands under the skin. Follicles connect the glands to the pores. Follicles are small sacs that produce and secrete liquid.
The glands produce an oily liquid called sebum. Sebum carries dead skin cells through the follicles to the surface of the skin. A small hair grows through the follicle out of the skin.
Pimples grow when these follicles get blocked, and oil builds up under the skin.
Skin cells, sebum, and hair can clump together into a plug. This plug gets infected with bacteria, and swelling results. A pimple starts to develop when the plug begins to break down.
Propionibacterium acnes (P. acnes) is the name of the bacteria that live on the skin and contributes to the infection of pimples.
Research suggests that the severity and frequency of acne depend on the strain of bacteria. Not all acne bacteria trigger pimples. One strain helps to keep the skin pimple-free.
A range of factors triggers acne, but the main cause is thought to be a rise in androgen levels.
Androgen is a type of hormone, the levels of which rise when adolescence begins. In women, it gets converted into estrogen.
Rising androgen levels cause the oil glands under the skin to grow. The enlarged gland produces more sebum. Excessive sebum can break down cellular walls in the pores, causing bacteria to grow.
Other possible triggers
Some studies suggest that genetic factors may increase the risk.
Other causes include:
- some medications that contain androgen and lithium
- greasy cosmetics
- hormonal changes
- emotional stress
Treatment depends on how severe and persistent the acne is.
Mild acne can be treated with over-the-counter (OTC) medications, such as gels, soaps, pads, creams, and lotions, that are applied to the skin.
Creams and lotions are best for sensitive skin. Alcohol-based gels dry the skin and are better for oily skin.
OTC acne remedies may contain the following active ingredients:
- Resorcinol: helps break down blackheads and whiteheads
- Benzoyl peroxide: kills bacteria, accelerates the replacement of skin, and slows the production of sebum
- Salicylic acid: assists the breakdown of blackheads and whiteheads and helps reduce inflammation and swelling
- Sulfur: exactly how this works is unknown
- Retin-A: helps unblock pores through cell turnover
- Azelaic acid: strengthens cells that line the follicles, stops sebum eruptions, and reduces bacterial growth. There is cream for acne, but other forms are used for rosacea.
It is advisable to start with the lowest strengths, as some preparations can cause skin irritation, redness, or burning on first use.
These side effects normally subside after continued use. If not, see a doctor.
Treating moderate to severe acne
A skin specialist, or dermatologist, can treat more severe cases.
They may prescribe a gel or cream similar to OTC medications but stronger, or an oral or topical antibiotic.
If an acne cyst becomes severely inflamed, it may rupture. This can lead to scarring.
A specialist may treat an inflamed cyst by injecting a diluted corticosteroid.
This can help prevent scarring, reduce inflammation, and speed up healing. The cyst will break down within a few days.
Oral antibiotics may be prescribed for up to 6 months for patients with moderate to severe acne.
These aim to lower the population of P. Acnes. The dosage will start high and reduce as the acne clears.
P. acnes can become resistant to the antibiotic in time, and another antibiotic is needed. Acne is more likely to become resistant to topical rather than oral antibiotics.
Antibiotics can combat the growth of bacteria and reduce inflammation.
Erythromycin and tetracycline are commonly prescribed for acne.
Oral contraceptives can help control acne in women by suppressing the overactive gland. They are commonly used as long-term acne treatments.
These may not be suitable for women who:
- have a blood-clotting disorder
- have a history of migraines
- are over 35 years old
It is important to check with a gynecologist first.
Topical antimicrobials also aim to reduce P. acnes in patients with moderate to severe acne. Examples are clindamycin and sodium sulfacetamide.
The dermatologist may prescribe a topical retinoid.
Topical retinoids are a derivative of vitamin A. They unclog the pores and prevent whiteheads and blackheads from developing.
Examples of topical retinoids prescribed in the U.S. are adapalene, tazarotene, and tretinoin.
This is a strong, oral retinoid, used for the treatment of severe cystic acne and severe acne that has not responded to other medications and treatments.
It is a strictly controlled medication with potentially serious side effects. The patient must sign a consent form to say that they understand the risks.
Adverse effects include dry skin, dry lips, nosebleeds, fetal abnormalities if used during pregnancy, and mood swings.
Patients who take isotretinoin must avoid vitamin A supplements, as these could lead to vitamin A toxicity.
Acne pimples vary in size, color, and level of pain.
The following types are possible:
- Whiteheads: These remain under the skin and are small
- Blackheads: Clearly visible, they are black and appear on the surface of the skin
- Papules: Small, usually pink bumps, these are visible on the surface of the skin
- Pustules: Clearly visible on the surface of the skin. They are red at their base and have pus at the top
- Nodules: Clearly visible on the surface of the skin. They are large, solid, painful pimples that are embedded deep in the skin
- Cysts: Clearly visible on the surface of the skin. They are painful and filled with pus. Cysts can cause scars.
Here are some tips for looking after skin that has acne or is prone to it.
- Wash your face no more than twice each day with warm water and mild soap made especially for acne.
- Do not scrub the skin or burst the pimples, as this may push the infection further down, causing more blocking, swelling, and redness.
- Avoid popping pimples, as this makes scarring likelier.
- A specialist can treat a pimple that requires rapid removal for cosmetic reasons.
- Refrain from touching the face.
- Hold the telephone away from the face when talking, as it is likely to contain sebum and skin residue.
- Wash hands frequently, especially before applying lotions, creams, or makeup.
- Clean spectacles regularly as they collect sebum and skin residue.
- If acne is on the back, shoulders, or chest, try wearing loose clothing to let the skin breathe. Avoid tight garments, such as headbands, caps, and scarves, or wash them regularly if used.
- Choose makeup for sensitive skin and avoid oil-based products. Remove makeup before sleeping.
- Use an electric shaver or sharp safety razors when shaving. Soften the skin and beard with warm soapy water before applying shaving cream.
- Keep hair clean, as it collects sebum and skin residue. Avoid greasy hair products, such as those containing cocoa butter.
- Avoid excessive sun exposure, as it can cause the skin to produce more sebum. Several acne medications increase the risk of sunburn.
- Avoid anxiety and stress, as it can increase production of cortisol and adrenaline, which exacerbate acne.
- Try to keep cool and dry in hot and humid climates, to prevent sweating.
Acne is a common problem. It can cause severe embarrassment, but treatment is available, and it is effective in many cases.