What Is Keratosis Pilaris?

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Keratosis pilaris is a common bumpy skin rash 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 and does not need to be treated unless you choose to do so.

The rash can occur at any age, but it is most common during adolescence. Keratosis pilaris tends to run in families, though the exact cause of the condition is not known.

Keratosis pilaris spread over the trunk
Keratosis pilaris spread over the trunk. IHUAN / Getty Images

Keratosis Pilaris Symptoms

Keratosis pilaris is an extremely common skin condition, affecting 50% to 80% of adolescents and around 40% of adults. 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.

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

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.

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.

Causes

Keratosis pilaris is caused by a buildup of keratin in the pores. Keratin is a fibrous protein that makes up your skin, hair, and nails.

For reasons not entirely unclear, 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.

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:

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 occurs more frequently in women than in men. It often develops during the early years of life, only to recede during childhood and re-emerge during puberty. For most people, keratosis pilaris will resolve in their 30s.

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. In addition to the follicular obstruction, there may be thin, short, crinkly hairs embedded in the outermost layer of skin (called the stratum corneum).

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

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

Treatment

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

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

Over-the-Counter Treatments

Keratosis pilaris can often be managed or improved with over-the-counter (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 of time until the irritation improves. Overuse can lead to skin atrophy (thinning), telangiectasias (spider veins), and hyperpigmentation (darkening of the skin).

Never treat a child's skin condition with medications intended for adults. If in doubt, speak with your child's pediatrician.

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.

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 doctor 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.

A Word From Verywell

As a cosmetic condition, so there's really no reason to treat keratosis pilaris unless you choose to. Keratosis pilaris usually starts improving on its own in the later teen years. While there is no cure for keratosis pilaris, OTC products and prescription medications may help improve the look and feel of the skin.

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