What Causes Keratosis Pilaris and How to Treat It

Keratosis pilaris is a common bumpy skin rash (sometimes called "chicken skin") that most often appears on the upper arms, thighs, cheeks, and buttocks. It is not contagious. Rather, it occurs when hair follicles on the body fill with dead skin cells instead of exfoliating normally.

It is typically diagnosed by appearance and is regarded as a cosmetic condition, meaning that it is harmless. While treatment isn't necessary, some medications are available that can help clear skin.

This article discusses the causes, symptoms, diagnosis, and treatment of keratosis pilaris.

What Causes Keratosis Pilaris?

Keratosis pilaris can occur at any age, but it is most common during adolescence. Keratosis pilaris tends to run in families and is caused by a buildup of keratin in the pores. Keratin is a fibrous protein that makes up your skin, hair, and nails.

Keratin will sometimes collect within a pore, creating a plug (called a keratotic plug). The obstruction causes the pore to swell and become inflamed, often trapping one or more hairs inside. Why keratin builds up in the pores of some people is not clear.

Some experts believe that keratosis pilaris is not solely the result of a keratotic obstruction. A 2012 study published in the International Journal of Trichology suggests that the condition is caused by circular hair shafts that damage the follicle wall and trigger inflammation.

Another study published in 2015 contends that abnormal or damaged sebaceous glands may be the triggering factor, causing the abnormal shedding of keratin in the secreted oils that moisturize and protect the skin.

Whatever the exact cause, keratosis pilaris is more common in people with:

• Xerosis (abnormally dry skin)
• Atopic dermatitis (eczema)
• Ichthyosis (a group of disorder characterized by scaly skin)
• Diabetes
• Obesity
• A family history of keratosis pilaris

Although a specific gene hasn't been identified, keratosis pilaris appears to run in families in an autosomal dominant pattern (meaning that only one parent is needed to pass on the disorder).

A variety of causal mutations have been proposed—including one involving the ABCA12 gene —although studies to date have been relatively small and inconclusive.

Keratosis Pilaris Symptoms

Keratosis pilaris rash may be skin-colored or may have a reddish, purplish, or brownish hue, depending on your complexion. The rash can appear anywhere on the body (except the palms of your hands and the soles of your feet), but it most often occurs on the:

• Upper arms
• Thighs
• Buttocks
• Cheeks

Keratosis pilaris tends to recur in episodes and often gets worse during the winter. This is true in both children and adults, although it does seem to eventually go away when children get older.

Keratosis pilaris doesn't hurt and typically doesn't itch. If itching does occur, it is usually mild.

In milder cases, you may only notice the bumps when running a hand over the affected skin. In other people, the rash may be visibly noticeable and the skin can be quite rough.

In babies and young children, the rash is most often seen on the cheeks and backs of the arms. In teens and adults, the backs of the arms and buttocks are the sites most commonly affected.

Who Gets Keratosis Pilaris?

Keratosis pilaris can occur at any age, but it is most common during adolescence. It is an extremely common skin condition, affecting 50% to 80% of adolescents and around 40% of adults.

Keratosis pilaris tends to run in families.

When to See a Healthcare Provider

Keratosis pilaris may need more than at-home treatment. If, after trying home and over-the-counter (OTC) remedies for a few weeks, you are not satisfied with the results, a dermatologist may be able to help.

Anytime you are concerned about a skin condition it's a good idea to consult your healthcare provider or a dermatologist.

Diagnosis

Keratosis pilaris is usually diagnosed based on the appearance and location of the rash. Dermatologists can get an up-close view using a magnifying tool known as a dermatoscope.

On rare occasions, a healthcare provider may perform a skin biopsy or other tests to rule out other conditions with similar features. These may include:

• Acne
• Eczema
• Psoriasis
• Seborrheic dermatitis
• Milia
• Folliculitis

You should always have an unidentified rash checked out by a healthcare provider to obtain the proper diagnosis and treatment. This is especially true for babies and younger children.

How to Get Rid of Keratosis Pilaris

Because keratosis pilaris is a cosmetic issue, there is usually no medical reason to treat it. Its appearance, however, may be bothersome to some.

The bumps may go away on their own or become less noticeable with age. They may also improve or disappear during the summer months.

At present, there is no cure for keratosis pilaris. However, there are medications and other measures you can take to make it much less noticeable. Treating keratosis pilaris may also help keep it from getting worse.

Home Remedies

There are a few lifestyle hacks that may improve the appearance of keratosis pilaris, including:

• Taking shorter, cooler baths or showers
  
• Gently exfoliating once or twice per week using a loofah, soft dry brush, or similar product
• Moisturizing directly after bathing using a product formulated for rough or bumpy skin
  
• Avoiding bumpy areas when shaving or waxing
• Wearing clothes made from natural, breathable materials (e.g., cotton, wool, linen)
  

Over-the-Counter Treatments

Keratosis pilaris can often be managed or improved with OTC products, including:

• Moisturizers: Because the rash tends to get worse with dry skin, moisturize twice daily, especially after bathing or showering. Moisturizers that contain urea or ceramides are especially useful.
• Exfoliating products: Gentle exfoliation helps loosen keratotic plugs and smooth the skin. Creams and body washes that contain alpha-hydroxy acids (such as lactic acid or salicylic acid) may be effective in unblocking pores. There are even exfoliating moisturizers that contain these ingredients. One example is Eucerin Intensive Repair Rich Lotion for Very Dry Skin.
• Soap substitutes: Bar soaps can be harsh on the skin and make a rash worse. Soap alternatives that are pH-balanced can prevent this by ensuring that the cleanser is neither too acidic nor too alkaline. They also lack many of the substances, like the foaming agent sodium lauryl sulfate, which may be allergenic. Cetaphil Gentle Skin Cleanser and CeraVe Body Wash are two such examples found on many market shelves.

Prescriptions

If OTC products aren't able to improve your keratosis pilaris, there are prescription medications that may help. These typically involve higher concentrations of lactic acid, salicylic acid, or urea. Examples include:

• Lac-Hydrin 12% ammonium lactate cream
• Vanamide 40% urea cream
• Keralac 47% urea cream

Topical retinoids, such as Tazorac cream (0.01% tazarotene) or Retin-A (0.025% to 0.1% tretinoin), are other treatment options. These medications help accelerate cell turnover rate, allowing new skin cells to come to the surface. The results can be highly variable. People with delicate skin may experience redness and irritation.

Topical steroids may be prescribed if the rash is extremely inflamed and bumpy. These are only used for a short period until the irritation improves. Overuse can lead to skin atrophy (thinning), telangiectasias (spider veins), and hyperpigmentation (darkening of the skin).

Specialist-Driven Procedures

A light-duty chemical peel using 70% glycolic acid may be considered if the appearance of the skin is causing distress. It involves a single, 5- to 7-minute application of glycolic acid followed by up to five days of recovery time.

A less common procedure is photopneumatic therapy in which pulsed blue light may provide relief of severe, treatment-resistant keratosis pilaris. A 2013 study published in the Journal of Drugs and Dermatology reported that the procedure, sometimes used to treat acne, reduced redness by 27% and bumpiness by 56% in 10 adults and children with keratosis pilaris.

Never embark on an aesthetic procedure like a chemical peel without first speaking with a dermatologist. Although estheticians are highly trained cosmetic professionals, they are not doctors or other healthcare providers.

Coping

Although keratosis pilaris is not a serious skin condition, it can cause embarrassment or self-consciousness in some who have it. People with keratosis pilaris often feel uncomfortable wearing sleeveless tops, shorts, or bathing suits and may even avoid physical contact with others.

If this sounds like you, it is important to remember that you are far from the only person with this condition. It is extremely common and generally self-limiting.

If keratosis pilaris is affecting how you feel about yourself, let your healthcare provider know. They may opt to treat your rash more aggressively to improve the quality of your skin as well as your overall well-being. If there is extreme redness, ask your dermatologist or an esthetician about hypoallergenic cosmetics that can help conceal inflamed skin.

It is also important to talk to trusted people in your life. Sometimes just airing your concern helps put things in perspective. If you think you could benefit from speaking to a professional, contact a therapist.

Summary

Keratosis pilaris is a bumpy skin rash usually found on the upper arms, thighs, cheeks, and buttocks. It is a harmless cosmetic condition and is not contagious. It occurs when hair follicles on the body fill with dead skin cells. Diagnosis is made via a physical examination. No treatment is necessary, but there are some at-home, OTC, and medical interventions that can help improve the look and feel of skin. Keratosis pilaris may resolve on its own with age.