Acne

What is acne?

Acne is a very common condition of the hair follicles and the oil glands attached to them. It produces blackheads and whiteheads, red and pus-filled spots, and, when more severe, deep and painful lumps. It most often affects the face, but the chest, back and shoulders are also commonly involved.

Who gets it?

Most people get acne of some kind at some stage, typically beginning around puberty. In many people it settles by the mid-twenties, but it can continue for longer or start for the first time after the age of 25. Adult acne is more common in women, where it often affects the lower face, jawline and neck.

What causes it?

Acne develops through several linked processes. The oil glands become over-sensitive to normal levels of hormones, particularly androgens, and produce more oil (sebum). Skin cells lining the hair follicle become sticky and block the opening, forming a plug. Bacteria that normally live on the skin, called Cutibacterium acnes, multiply in the blocked follicle, and the immune system reacts, causing inflammation.

Factors that can make acne worse include hormonal changes around periods, polycystic ovary syndrome, some contraceptives, certain medicines such as steroids, anabolic steroids and some anti-epileptic medicines, heavy or greasy skincare and hair products, friction or pressure from headbands, helmets or phone use, and picking or squeezing spots. In most people diet does not play a major role, although some studies suggest a link with high milk intake and high-sugar (high glycaemic index) foods.

Acne is not caused by poor hygiene or by having dirty skin. Over-washing and harsh scrubbing can make it worse.

Is it hereditary or contagious?

Acne often runs in families, particularly when both parents had acne, although many people with acne have no affected relatives. Genes, hormones and lifestyle usually all play a part. Acne is not contagious.

What does it look and feel like?

Acne includes several types of spot. Blackheads are open, blocked pores with a dark surface. Whiteheads are closed, small, skin-coloured bumps. Inflammatory spots include red or darker raised bumps (papules) and spots with a yellow or white centre (pustules). More severe acne causes nodules and cysts, which are larger, deeper, painful lumps under the skin.

Acne can be sore and tender. As spots heal, they can leave marks. On brown and black skin, dark marks (post-inflammatory hyperpigmentation) are particularly common and can last for many months. On lighter skin, red or purple marks can persist after spots settle.

Acne can also cause permanent scarring, either pitted scars (such as ice pick, rolling and boxcar scars) or raised scars, including keloids, particularly on the chest, back and jawline. The risk of scarring is higher with deeper, more inflamed acne and with picking.

The emotional impact

Acne can have a significant effect on self-esteem, confidence, mood and social life, regardless of how severe it looks to others. Anxiety and low mood are common. These feelings are important to raise, as they are part of how acne is assessed.

How is it diagnosed?

Acne is diagnosed from its appearance. Blood tests are not usually needed, but in women with signs of hormonal imbalance, such as irregular periods or excess hair growth, tests for conditions such as polycystic ovary syndrome may be suggested. Several other conditions can look like acne, including rosacea, perioral dermatitis and folliculitis, so an accurate diagnosis matters.

What is the outlook?

Acne usually improves with time, and there are many effective treatments. Getting acne under control early reduces the risk of long-term marks and scarring.

How is it Treated?

Dr Mounsey will assess the type and severity of your acne, the risk of scarring, and any hormonal factors. Treatment is tailored to you and may include topical treatments such as retinoids, benzoyl peroxide, azelaic acid and combination gels. Moderate acne is often treated with an antibiotic tablet alongside a topical treatment, and hormonal treatments such as the combined contraceptive pill or spironolactone can help some women. For severe acne, or acne that is scarring or not responding, isotretinoin is very effective, and Dr Mounsey will supervise this with the required monitoring and safety checks.

More information

British Association of Dermatologists patient leaflet: https://www.bad.org.uk/pils/acne

This page gives general information only and is not a substitute for a consultation. Everyone's skin is different, and what is right for you will depend on your own circumstances. If you are worried about a skin problem, please book an appointment with Dr Mounsey or speak to your GP. If you have a mole or skin lesion that is changing, bleeding or growing quickly, please seek medical advice promptly.