Keratosis pilaris: the “little bumps” on the arms and what helps

Small rough dots on the back of the arms, like goosebumps that never go away. Sometimes reddish, sometimes on the thighs or buttocks, almost always rough to the touch like fine sandpaper. Many people think they are spots, try to squeeze them, scrub hard, and the dots are still there.

The name is keratosis pilaris, and it is one of the most common skin conditions there are. It is not contagious, it is not a lack of hygiene and it is not dangerous. Nor does it have a definitive cure, but it responds well to a simple, consistent routine.

What it is and why it appears

Every body hair emerges from a small opening in the skin, the hair follicle. In keratosis pilaris, keratin (the protein that forms the outermost layer of the skin) builds up at the opening of these follicles, forming small plugs. Sometimes the hair is coiled up beneath the plug and some redness may appear around it.

Who gets it

• Very common in childhood and adolescence. Studies point to about half to three quarters of adolescents, depending on the population.
• An important proportion of adults keep it, generally in a milder form.
• Slightly more frequent in women.
• Associated with dry skin, atopic dermatitis (eczema) and ichthyosis vulgaris, a hereditary condition of very dry, scaly skin.
• A strong family component. Often, parents or siblings have it too.

Why it happens

The exact cause is not fully understood, but there are several clues:

• Fragile skin barrier. Changes in the filaggrin gene, a protein essential to the skin barrier, are more frequent in people with keratosis pilaris, as in atopic dermatitis and ichthyosis vulgaris.
• Dry skin, which favours the build-up of keratin.
• Changes in the hair itself, which in some people seems to grow curled up.
• Hormones, which would explain the higher frequency in adolescence and the worsening in some periods, such as pregnancy.

Course

• Worse in winter, with cold, dry air and heating.
• Improves in summer, with humidity and sun (which is no reason to expose yourself without sunscreen).
• Tends to fade with age, often clearly after the age of 30.

How to recognise it

• Small dots (1 to 2 mm), rough to the touch, centred on a pore.
• Skin colour, whitish, pinkish or red; in darker skin, sometimes brownish.
• Typical distribution: back and sides of the arms, front of the thighs, buttocks; in children, also on the cheeks.
• Symmetrical (both arms, both thighs).
• Usually without pain and with little or no itching.

Variants

• “Rubra” keratosis pilaris: with more marked redness around the dots.
• Keratosis pilaris “alba”: rough dots without redness.
• On children's faces: rough spots and redness on the cheeks, sometimes mistaken for acne or irritated skin.
• Rarer forms, with loss of hair in the eyebrows or scarring, which should be assessed by a dermatologist.

What it can be confused with

If you have doubts, if the spots have pus, pain, intense itching or spread quickly, seek assessment.

The routine at home that works

Keratosis pilaris has no definitive cure, but the combination of two simple principles usually improves the texture a great deal: gently dissolving the keratin plugs and reinforcing the skin barrier. The key is regularity: results appear in 4 to 8 weeks and disappear if the routine is stopped.

1. A keratolytic cream, every day

These are creams that soften and help remove excess keratin. The ingredients with the most evidence:

Sources: Wang and Orlow, 2018; Hwang and Schwartz, 2008; Kootiratrakarn et al., 2015.

Apply once a day, after the bath, to the affected areas. If it stings a lot, use it every other day, or alternate with a simple moisturiser.

2. Generous moisturising

On the days or in the areas where you do not use the keratolytic, an emollient cream with ceramides, glycerine or petroleum jelly reinforces the barrier. Applying it with the skin still slightly damp, within three minutes of the bath, improves water retention.

3. A bath that works for your skin

• Warm water, not hot.
• A short shower, 5 to 10 minutes.
• Gentle shower gel, without alkaline soap, or bath oil.
• Pat dry with a towel, without rubbing.

More on this topic in Dry skin on the body: the bathing mistakes that make it worse.

4. Mechanical exfoliation: only gentle and little

A soft bath mitt or a gentle sponge, once or twice a week, with light movements, can complement this. Grainy scrubs, hard brushes or rough mitts used with force irritate the skin, increase redness and may worsen its appearance. See Exfoliating the body: when, how and with what.

5. Topical retinoids, in resistant cases

Retinoids such as tretinoin or adapalene can help normalise skin renewal at the opening of the follicles. They are usually reserved for cases that do not respond to the routine above, because they can irritate. They must not be used during pregnancy. Speak to a doctor before using them.

6. Environment

In winter, heating dries the air. A humidifier in the bedroom and cotton clothing can help.

Common mistakes

• Squeezing the bumps. They are not spots. Squeezing inflames, can infect and leave marks.
• Scrubbing hard. The skin looks smoother at the time, but becomes irritated and redder.
• Very hot, long baths. They remove the skin's lipids and worsen dryness.
• Alkaline or perfumed soaps.
• Giving up after a week. Improvement takes weeks.
• Stopping the routine when it improves. Keratosis pilaris comes back; maintenance may be less frequent, but should continue.
• Dry shaving with a razor on affected areas, which can irritate and cause ingrown hairs.

Treatments in the clinic

When the routine at home is not enough, especially for persistent redness or very marked texture, there are options:

• Superficial chemical peels (glycolic, lactic or salicylic acid) in a series, to improve texture.
• Gentle microdermabrasion, with care not to irritate.
• Lasers and pulsed light aimed at the vessels, for the redness of “rubra” keratosis pilaris (Schoch et al., 2016); and hair-removal lasers, which in some small studies improved texture by reducing the ingrown hairs in the follicles (Ibrahim et al., 2015).

Results are variable and maintenance at home is still necessary. Darker skin requires special care, because of the risk of discolouration.

At Luxmed, we confirm whether it really is keratosis pilaris, help you set up a simple, effective routine at home and, when it makes sense, propose treatments in the clinic for texture and redness.

This article is for information purposes and does not replace a consultation. The results of any treatment vary from person to person.

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