Keratosis Pilaris

Keratosis pilaris (KP) is a very common and may be present in half the population. It is a completely harmless skin condition. It affects 50-70% of adolescents and approximately 40% of adults.

Its name gives some idea of what it is; ‘keratosis’ means that there is too much keratin, which makes up the tough horny outer layer of the skin, while ‘pilaris’ comes from the Latin for hair (pilus).

In keratosis pilaris, many small (1 to 2 mm across) horny plugs can be seen blocking the hair follicles on the upper and outer parts of the arms and thighs. This condition can look like goosebumps but feels slightly rough.

Keratosis pilaris appears when extra keratin accumulates in the hair follicles. This problem usually starts in childhood and becomes more evident during adolescence and adulthood.

For reasons not fully understood, the condition seems to be better in the summer than in the winter, perhaps because in winter, the skin often gets dry while in summer, the sweat makes it less dry.

Keratosis pilaris may be associated with Ichthyosis Vulgaris and atopic eczema; however, this may be coincidental.

Causes of keratosis pilaris are not fully understood, but it is genetic in more than half those who are affected. Keratosis pilaris is harmless and is not infectious but can cause emotional discomfort.

It is usually found in more than one member of a family. The way it is inherited varies from family to family, but it often fits into an ‘autosomal dominant’ pattern; this means that there will be a 1 in 2 chance that each child of an affected parent will inherit the condition.

Some people find their keratosis pilaris looks unattractive. The skin feels rough, dry, and appears as though it has permanent goosebumps. Occasionally keratosis pilaris is itchy. 

The groups of small bumps are most common on the backs of the upper arms and the fronts of the thighs. Sometimes keratosis pilaris also affects the buttocks and lower back and chest and, in less common forms, the face and eyebrows. Some redness may appear around the small bumps.

There are no specific tests for keratosis pilaris; however, your doctor will recognize it easily. A biopsy is seldom needed and would be requested by your dermatologist, mainly if it is associated with acne or eczema that do not get better with treatment. Other conditions look similar to KP, and the biopsy will confirm the diagnosis.

No, however, it often (but not always) does clear up during adult life.

No treatment clears keratosis pilaris completely, but it can improve the condition temporarily. Emollients (moisturizers) can be of benefit. Creams containing salicylic acid, lactic acid, or urea are useful.