Horripilation from the cold on legs
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Goose bumps occur when tiny muscles within your hair follicles contract, usually in response to cold, fear or another intense emotion. Many people experience a persistent or recurring skin rash that resembles goose bumps, due to involvement of the hair follicles. A condition called keratosis pilaris (KP) is the most likely culprit, although other skin disorders can sometimes cause a similar appearance. KP does not pose a health threat, but can be bothersome. This skin condition can usually be controlled with relatively simple measures.

Keratosis Pilaris Defined

With keratosis pilaris, an accumulation of a protein called keratin plugs the opening of the hair follicles at the skin surface. This leads to tiny, rough bumps that resemble goose flesh. The bumps can be flesh colored or slightly pink. The keratin plug sometimes traps the hair within the follicle, and the coiled hair might be visible below the skin surface. A KP rash might cause mild itchiness, however many with the condition do not experience this symptom. Although the appearance of KP can be disconcerting, the rash is medically harmless. KP can develop on any skin surface with hair follicles, but most frequently occurs on the back of upper arms, the front of the thighs and the buttocks. It also might appear on the outer aspect of the forearm, the cheeks and the trunk.

People Affected by KP

KP is a very common skin condition. Approximately 40 percent of adults have some degree of KP, according to a study published in the Fall 2012 issue of the "International Journal of Trichology." The condition is even more common among adolescents, affecting 50 to 80 percent. KP tends to run in families, occurs in people of all races, and affects females slightly more often than males. People with asthma, hay fever, eczema, dry skin or another chronic skin disorder may be more likely to develop KP. Those who are overweight or obese are also at increased risk.

KP Time Frame and Course

KP usually begins during childhood and continues into adulthood in many people. However, the severity of KP tends to diminish with age. Many adults have only mild KP in one or two areas. The rash might come and go, especially in response to environmental or seasonal changes. As dry skin tends to aggravate KP, some people find the rash is worse in the winter months when the relative humidity is low. However, people with chronically dry skin and those who live in areas with low humidity year-round might not experience any seasonal variation. KP does not typically cause permanent skin damage, but habitual scratching or picking at KP bumps can potentially lead to scarring. In people with moderate to severe to KP, the affected skin might darken or lighten, although this is uncommon.

KP Treatment

A mild KP rash is often inconspicuous and unnoticeable unless inspecting the skin closely. Treatment for KP is not medically necessary. However, some people with the condition who experience associated itchiness or find the rash cosmetically unacceptable seek treatment. KP management recommendations often include: -- use of a mild skin cleanser rather than soap -- application of a moisturizer containing urea or lactic acid, 2 to 3 times daily -- skin exfoliation during bathing with a loofah, sponge or comparable product

If these measures don't provide sufficient improvement, your doctor might recommend a topical prescription medicine to promote exfoliation. If all other forms of treatment fail, laser therapy might be an option.

Warnings and Other Considerations

Skin rashes can sometimes be challenging to diagnose, even for doctors. Although KP is usually relatively easy to identify, other skin conditions can appear similar, such as folliculitis or even acne. Therefore, it's advisable to see your doctor for an accurate diagnosis. This is especially important if you're an adult and the goose bump-like rash is a new development. Additionally, some skin conditions that mimic KP can be potentially serious. Seek medical care right away if you develop a new rash accompanied by any warning signs and symptoms, including: -- fever or chills -- pain at the site of the rash -- pus or other liquid drainage from the bumps -- coalescence of the bumps or blister formation -- shortness of breath or difficulty breathing

Reviewed and revised by: Tina M. St. John, M.D.