Keratosis pilaris is a common and harmless condition where the skin becomes rough and bumpy, as if covered in permanent goose pimples.
There's no cure for keratosis pilaris, but there are things you can do to improve the rash, such as using soap-free cleansers and gently exfoliating (removing dead skin cells from the surface of the skin).
There's no real need to see your GP unless the condition is causing you concern. It will usually improve as you get older and will sometimes disappear completely in adulthood.
This page provides more information on keratosis pilaris and explains what you can do if you think you have it or if you've just been diagnosed with it.
Where keratosis pilaris occurs
Keratosis pilaris most commonly affects the back of the upper arms, and sometimes the buttocks and front of the thighs. Less often, the forearms and upper back may be affected.
There are also rare variants of keratosis pilaris that can affect the eyebrows, face and scalp, or the entire body.
How it affects the skin
The patches of affected skin will be covered in tiny spiky bumps, which may be white, red or skin-coloured. This spotting looks like "chicken skin" or permanent goose pimples, and the skin feels rough, like sandpaper.
In some people, the skin will itch and there may be some inflammation and pinkness around the bumps.
Keratosis pilaris is not contagious (it cannot be spread from person to person).
The skin tends to improve in summer and get worse during winter months or dry conditions.
Who is affected
Keratosis pilaris is very common, affecting up to one in three people in the UK. It can affect people of all ages but it is particularly common in:
children and adolescents
people with eczema or a condition called ichthyosis (thick, dry scaly skin)
people of Celtic origin
The condition typically starts during childhood (although it can sometimes occur in babies), and gets worse in adolescence, around puberty.
Keratosis pilaris sometimes improves after puberty, and it may even disappear in adulthood, although many adults still have the condition in their 40s and 50s. It's uncommon in elderly people.
What causes keratosis pilaris?
Keratosis pilaris runs in families and is inherited from your parents. If one parent has the condition, there is a one in two chance that any children they have will also inherit it.
Keratosis pilaris occurs when too much keratin builds up in the skin's hair follicles. Keratin is a protein found in the tough outer layer of skin, which causes the surface of the skin to thicken (hence the name "keratosis").
The excess keratin blocks the hair follicles with plugs of hard, rough skin. The tiny plugs widen the pores, giving the skin a spotty appearance.
It is often associated with other dry skin conditions, such as eczema and ichthyosis, which make the rash worse.
Treating keratosis pilaris
There is little that can be done to treat keratosis pilaris, and it often gets better on its own without treatment.
However, if it is bothering you, the following measures may help improve your rash:
Use non-soap cleansers rather than soap – ordinary soap may dry your skin out and make the condition worse.
Moisturise your skin when it's dry –your GP or pharmacist will be able to recommend a suitable cream. However, moisturisers and emollients will only reduce the dryness of your skin and will not cure the rash. Creams that contain salicylic acid, lactic acid or urea are thought to be the most effective.
Gently rub the skin with an exfoliating foam pad or pumice stone to exfoliate the rough skin – be careful not to scrub too hard and rub off layers of skin.
Take lukewarm showers rather than hot baths.
You can also ask your GP about 'off label' treatments that may help. These are products that haven't been officially approved and licensed for treating keratosis pilaris, but are sometimes used because they have helped people in the past. Examples include:
creams containing retinol (which is derived from vitamin A)
microdermabrasion – a cosmetic exfoliation treatment which is sometimes offered in health spas
There is no strong evidence to suggest that these therapies are effective treatments for keratosis pilaris. You may also have to pay for some of them privately.
Keratosis pilaris, also known as "chicken skin", on the top of the arm