Keratosis pilaris

Also called Chicken skin, KP

Rough bumps on the upper arms and thighs. Extremely common, harmless, and improved by moisturising rather than by scrubbing.

What it is

A very common, harmless condition in which keratin plugs the hair follicles, producing small rough bumps that feel like sandpaper or gooseflesh.

It affects the backs of the upper arms most often, and also the thighs, buttocks and cheeks. It is extremely common, affecting perhaps a third or more of people at some point, and is most noticeable in childhood and adolescence, often improving with age.

It runs in families and is more common in people with eczema, ichthyosis and dry skin generally.

**It is not an infection, not caused by poor hygiene, and cannot be scrubbed away.** Vigorous exfoliation makes it redder and more inflamed, and this is the commonest self-inflicted worsening.

It cannot be cured. It can be improved, and the effective approach is consistent moisturising, particularly with products containing urea, lactic acid or salicylic acid, which soften the plugs.

On the cheeks in children it can cause redness that is mistaken for eczema or acne.

A less common variant causes redness and, over years, scarring hair loss of the eyebrows, and that one is worth treating actively.

Signs you might notice

Small, rough, skin-coloured, red or darker bumps around hair follicles.

Usually on the backs of the upper arms, and often the thighs, buttocks and cheeks.

A sandpaper texture.

Sometimes mild itching.

Worse in winter and in dry conditions, better in summer and humidity.

Not painful, not infectious, and no discharge.

See a GP if: it is very red and inflamed; there is scarring or hair loss, particularly of the eyebrows; it is itchy and troublesome; or the diagnosis is uncertain.

Different, and needing assessment: painful spots, pustules with surrounding redness, or lesions that are crusted or spreading, which suggests folliculitis or infection.

How it can affect day-to-day life

The main harm is to confidence, particularly in teenagers who avoid short sleeves. The condition is trivial medically and not trivial to the person, and dismissing it is unhelpful.

Expectations matter: improvement rather than clearance is realistic, and it takes weeks of consistent use to see a difference.

Scrubbing, exfoliating brushes and harsh products make it worse. Gentle is the rule.

Short lukewarm showers, soap substitutes and moisturising immediately after patting dry works better than any single product.

Urea-containing creams, from around 10 per cent upwards, are the most useful and are available over the counter.

It flares in winter and settles in summer, so a seasonal routine makes sense.

Picking causes darker marks and sometimes scarring, particularly on brown and black skin, where post-inflammatory pigmentation is prominent and slow to fade.

Supporting someone well

Do not scrub or exfoliate harshly; it worsens the redness.

Moisturise daily, straight after a lukewarm shower, on damp skin.

Use a cream containing urea, lactic acid or salicylic acid for the roughness.

Use a soap substitute rather than soap or shower gel.

Give it several weeks before judging, and expect improvement rather than cure.

Do not pick; it causes marks and scarring.

Treat associated eczema and dry skin.

See a GP for the scarring variant affecting the eyebrows, which needs active treatment.

Reassure teenagers that it is very common and tends to improve with age.

Where to get help

A pharmacist for urea-based creams and emollients.

A GP practice for inflamed, itchy or scarring forms, or where the diagnosis is unclear.

British Association of Dermatologists publish a patient leaflet on keratosis pilaris.