Keratosis pilaris (KP, also follicular keratosis) is a very common genetic follicular condition that is manifested by the appearance of rough bumps on the skin, hence referred to as chicken skin. It most often appears on the back and outer sides of the upper arms (though the lower arms can also be affected), and can also occur on the thighs and tops of legs, flanks, buttocks, or any body part except glabrous skin (like the palms or soles of feet). Less commonly, lesions appear on the face, which may be mistaken for acne.
Worldwide, KP affects an estimated 40% of the adult population and approximately 50%-80% of all adolescents. It is more common in women than in men. There are several different types of keratosis pilaris, including keratosis pilaris rubra (red, inflamed bumps), alba (rough, bumpy skin with no irritation), rubra faceii (reddish rash on the cheeks), and related disorders. While KP resembles goose bumps, it is characterized by the appearance of small rough bumps on the skin. As a result, many people with keratosis pilaris do not know they have it, and it is often confused with acne.
Keratosis pilaris occurs when the human body produces excess keratin, a natural protein in the skin. The excess keratin, which is cream color, surrounds and entraps the hair follicles in the pore. This causes the formation of hard plugs (process known as hyperkeratinization). Bearing only cosmetic consequence, the condition most often appears as a proliferation of tiny hard bumps that are seldom sore or itchy. Though people with keratosis pilaris experience this condition year-round, it is during the colder months, when moisture levels in the air are lower, that the problem can become exacerbated and the goose bumps are apt to look and feel more pronounced in color and texture. Many KP bumps contain an ingrown hair that has coiled. This is a result of the keratinized skin's "capping off" the hair follicle, preventing the hair from exiting. The hair, then, grows inside the follicle, often encapsulated. The hair can be removed, much like an ingrown hair, though removal can lead to scarring.
There is currently no known cure for keratosis pilaris. However, there are effective treatments available that make its symptoms less apparent. The condition often improves with age and can even disappear completely in adulthood, though some will show signs of keratosis pilaris for life. Most of the available treatments are purely symptomatic; the one thing they all have in common is need for repetition and ongoing commitment. Some seeking treatment with the disorder may be prescribed Tretinoin or Triamcinolone cream, often by request.
Triamcinolone, most commonly sold under the trade name Aristocort, is a synthetic corticosteroid medically approved as an anti-inflammatory agent in the treatment of eczema, which also reduces the amount of keratin in pores. It may be of most help to those with keratosis pilaris by reducing red, inflamed bumps. Triamcinolone is typically applied three times a day.
Tretinoin, most commonly sold under the trade name Retin-A, is a topical retinoid medically approved in the treatment of acne. This medicine works by causing the outer layer of the skin to grow more rapidly, which decreases the amount of the protein keratin in the skin. As a result, the surface layer of the skin becomes thinner and pores are less likely to become blocked, reducing the occurrence of symptoms related to acne. As keratosis pilaris is manifested through excess keratin in the skin, Tretinoin forms a more effective and core approach to treatment than Triamcinolone, which forms a largely symptomatic approach. Tretinoin is typically applied once a day before bed.
An alternative treatment is Adapalene, a retinoid medication that is a more stable compound, is less sunlight-sensitive, has fewer general side-effects, and may be just as effective as Retin-A. Treatment of KP with Adapalene would be considered an "off-label" use of the medication.
As with Triamcinolone, Tretinoin or any other treatment, once therapy is discontinued, the condition reverts to its original state. However, skin treated with Tretinoin may take several weeks or more to revert to its pre-treatment condition, but may, at the same time, take several weeks or more to show optimal results, with the condition commonly worsening initially, as underlying keratin is brought to the surface of the skin. Tretinoin is considerably more expensive and dispensed in smaller quantities than Triamcinolone and other treatments. Although it may be the most effective treatment for keratosis pilaris, it is not considered the first line of treatment.
Keratosis pilaris has not been clinically researched for treatment in an unbiased manner, with all claims of success or improvement being purely marketed or anecdotal. The condition is often dismissed outright by practitioners as being presently untreatable giving mere moisturizing suggestions or reassurance that the condition will improve or cease with age, typically after 30. General practitioners are often unable to identify the condition. Ignorance, accompanied with the price, availability, quantity dispensed, time taken for optimal results to be achieved, more serious side-effects, adverse reactions, and worsening of the condition in the initial treatment phase − coupled with the cheaper, safer, and easier availability of other treatments − has hindered Tretinoin from showing its potential in the treatment of this condition.
Exfoliation, intensive moisturizing cremes, lac-hydrin, creams, and lotions containing alpha hydroxy acids and urea may be used to temporarily improve the appearance and texture of affected skin.
Beta hydroxy acids may help improve the appearance and texture of the afflicted skin. Milk baths may provide some cosmetic improvement due to their containing lactic acid, a natural alpha hydroxy acid in milk. Sunlight may be helpful in moderation. Coconut oil may also be helpful if applied to afflicted areas while in the shower. Scratching and picking at KP bumps causes them to redden, and, in many cases, will cause bleeding. Excessive picking can lead to scarring. Wearing clothing that is looser around the affected areas can help reduce the marks, as constant chafing from clothing, such as tight-fitting jeans, is similar to repeatedly scratching the bumps.