Why do people get acne?

What happens inside a blocked pore?

A pore is the opening of a hair follicle, which contains a hair and connects to an oil gland. The gland produces sebum, the oil that helps keep skin from drying out. Normally, oil reaches the surface and old skin cells shed. In acne, oil and skin cells stick together inside the follicle instead. Bacteria grow in the blockage, and inflammation causes swelling, warmth, colour changes and pain. If the follicle wall breaks, its contents spill into nearby skin and create a more inflamed spot. Acne is therefore more than excess oil sitting on the surface.4

Why do some spots look different?

• Whiteheads are blocked follicles that remain beneath the surface.
• Blackheads are blocked follicles open at the surface. Air darkens the oil; the black colour is not dirt.
• Papules are raised, inflamed bumps. They can look pink or red on white skin, and brown or purple on brown and black skin.
• Pustules are raised bumps containing pus.
• Nodules and cysts are larger lumps beneath the skin that can be painful.

Why does acne start during puberty or continue into adulthood?

During puberty, hormones called androgens increase in both boys and girls. They make oil glands larger and increase oil production, creating more opportunity for follicles to become blocked. Hormonal changes around periods, pregnancy and menopause can also contribute to acne. Acne during the teenage years is more common in males, while acne that continues into adulthood is more common in women. Having parents who had acne also increases your likelihood of developing it. Age and family history help explain susceptibility, but neither tells you exactly how severe acne will become.14

Certain medicines can cause acne, including corticosteroids, lithium and medicines containing hormones. Some hormonal contraceptives help acne, while others can make it worse. If breakouts begin after a medicine change, bring the timing and your medication list to a clinician so they can assess the connection.345

What can make acne worse?

Stress can worsen existing acne, but it does not cause acne by itself. Pressure from helmets, tight clothing and backpacks can aggravate breakouts, as can high humidity and environmental irritants. Sports equipment can cause a form called acne mechanica. Greasy skincare and hair products can also contribute, including bumps along the hairline and forehead. Scrubbing, squeezing and picking make matters worse rather than clearing the underlying blockage. For body acne, loose, breathable clothing is a practical choice, especially during exercise or sweating.1246

Does chocolate or greasy food cause acne?

Chocolate and greasy foods are often blamed, but there is little evidence that food has a large effect on acne in most people. Some studies link acne with skim milk, whey protein and diets high in sugar. Diet could worsen acne for some people, but the relationship is still being studied. These links are not a reason to assume every breakout came from your last meal or to remove whole food groups automatically. Acne has several contributing factors, and a food explanation should not replace treatment for persistent or painful spots.245

How many people have acne?

Acne is very common, particularly in teenagers and young adults. Estimates differ: about 95% of people aged 11 to 30 are affected to some extent in one estimate, while another puts at least mild acne at about 80% in that age group. These are estimates of being affected, not counts of people with acne on a particular day. People of all ages and races can get acne. It often settles by the thirties, but some people continue to have it in their forties and fifties.457

What should you do each day?

A basic routine does not require lots of fancy products, even if the bathroom shelf is accepting applications. Noncomedogenic means designed not to clog pores, which is a more useful job description than another vague promise on a bottle.7

1. 1Wash gently with a mild, fragrance free cleanser, up to twice a day. Remove makeup at the end of the day and avoid scrubbing or repeated washing.
2. 2Pat skin dry and apply a moisturiser suited to your skin. A gel moisturiser is an option for oily or acne prone skin.
3. 3Choose water based, noncomedogenic skincare and makeup rather than greasy products.
4. 4Use sunscreen with SPF 30 or higher outdoors. Sunbathing and sunbeds are not acne treatments, and many acne medicines increase sensitivity to sunlight.

Which treatments address the blockage?

For a few blackheads, whiteheads or pimples, a pharmacist can help choose a treatment. Salicylic acid helps remove dead skin cells that clog follicles. Benzoyl peroxide targets bacteria that aggravate acne; lower concentrations and wash formulations are less irritating. Retinoids help clear blackheads and whiteheads and prevent new blockages. They treat the affected area rather than just individual spots. More widespread or severe acne can need prescription creams, gels or tablets that address inflammation, bacteria, oil production or hormones.157

Follow the product directions carefully and apply acne medicines sparingly. Treatment responses can take 6 to 8 weeks, and retinoids can take several months to show positive results. Redness, dryness and excessive peeling are possible side effects. Benzoyl peroxide can bleach towels and clothing. Acne can flare again even after it responds to treatment.35

Pregnancy can trigger acne, but treatment choices need particular care. Oral isotretinoin must not be taken during pregnancy because it causes severe birth defects. Isotretinoin also requires close medical monitoring because of its side effects.3

When should you see a doctor?

See a doctor for deep or painful lumps, many spots, scarring, worsening acne or acne that is not improving with treatment. Hot, swollen and red skin can indicate infection; redness can be harder to see on brown and black skin. Sudden, severe adult acne also deserves assessment for an underlying cause. Seek help if acne is affecting your mood or mental health, even if the spots look mild. A doctor can offer prescription treatment or refer you to a dermatologist, a specialist in skin conditions.15