Why does keratosis pilaris happen?

What makes the bumps form?

A hair follicle is the opening in your skin where a hair grows. In keratosis pilaris, keratin collects in the upper part of the follicle instead of shedding away normally. The resulting hard plugs create small bumps and a rough texture. When many follicles become blocked, the skin feels like a patch of sandpaper rather than a single spot.234

The bumps usually appear on the upper arms, thighs or bottom, although the face and other areas can be affected. They are usually painless and can be skin coloured, red or darker than the surrounding skin. Facial bumps can be mistaken for acne. Keratosis pilaris is harmless and not contagious, so you cannot catch it from someone or pass it on.124

Why do some people get it?

Keratosis pilaris often runs in families. Having a parent or another close blood relative with it increases your chances. Researchers have also found links with changes in filaggrin, a protein that helps the skin barrier work. Genetics helps explain the pattern, but the exact cause of the keratin buildup remains uncertain.34

People of all ages and races can have keratosis pilaris, but it commonly begins before age two or during the teenage years. Hormones can trigger another flare around puberty. Dry skin, eczema, asthma and hay fever are associated with a greater chance of developing it. These are risk factors, not requirements: having keratosis pilaris does not mean you have another condition.3

Why is it worse in winter?

Dry skin makes keratosis pilaris worse. The bumps tend to become more noticeable in winter, probably because the air contains less moisture, and can improve in summer. Hot showers, drying bathing products and harsh scrubbing can also worsen the skin. Scrubbing harder is not a solution to the underlying tendency to form plugs.1245

What can you do about the buildup?

Treatment is optional because keratosis pilaris is harmless. If the texture bothers you, care focuses on reducing dryness and loosening the plugs. Moisturizing lotions can soothe skin and improve its appearance, a useful job even without a dramatic product name.25

1. 1Wash with lukewarm water and a mild, unperfumed bathing product. Keep showers to 15 minutes or less.
2. 2If you exfoliate, use a washcloth gently rather than a harsh scrub. Do not pick, scratch or rub the bumps.
3. 3Apply moisturizer after bathing while the skin is still damp, and use it daily. It can also be applied several times throughout the day.
4. 4For persistent roughness, ask a pharmacist about a cream containing urea, lactic acid or salicylic acid. These ingredients moisturize or help loosen the scale in blocked follicles.

Will it go away?

Improvement often takes months, so the moisturizer has a longer assignment than its advertising usually suggests. Bumps are likely to return if you stop using treatment. There is no cure, but keratosis pilaris can gradually fade with age. Some cases that begin in the teenage years clear by the mid twenties; others continue into adulthood.234

When should you get the bumps checked?

Speak to a pharmacist if the skin becomes itchy or inflamed, or see a doctor if bothersome bumps do not improve with lotions. Painful bumps are not typical of keratosis pilaris and need assessment rather than more scrubbing. A clinician can usually identify keratosis pilaris by examining the skin; tests are often unnecessary.125