Keratosis pilaris (KP) is not dangerous, but some people may find the bumps unsightly.
In this article, we examine what the bumps look like, what causes them, and what treatment options exist for them.
Keratosis pilaris is characterized by small red or white bumps on the skin. Image credit: Irja from San Francisco (2007, April 3).
KP appears as small, rough bumps on the skin. The bumps may be white or red and are often accompanied by dry, scaly skin. Some people with KP remark that the bumps look like chicken flesh or goosebumps.
Most people first notice symptoms as children or teenagers, and KP is more common among young people than adults.
KP can appear anywhere on the body that has hair follicles. The most common sites for KP include:
- upper arms (in 92 percent of cases)
- thighs (in 59 percent of cases)
- buttocks (in 30 percent of cases)
KP bumps often have a visible white "head." But unlike acne and some other skin bumps, the clogged pore is not due to an infection or bacteria. KP bumps occur when keratin, a protective skin protein, builds up and clogs hair follicles.
Causes and risk factors
KP may be more likely to occur in cold and dry climates.
A buildup of keratin is the immediate cause of KP. However, researchers are unsure why some people develop this excess keratin, and others do not. People with dry skin, eczema, and skin allergies are more likely to develop KP than others.
During the winter months, when skin tends to be drier, people prone to KP may have more outbreaks. Dry, cold climates can also make KP worse.
KP also appears to have a genetic component. Research suggests the tendency to develop KP is a genetically dominant trait, which means that people who have one parent with KP are at a significant risk of developing the condition themselves.
Other researchers do not agree that that KP is simply due to the buildup of keratin. A 2012 study looked at 25 people with a history of keratosis pilaris and found that the hair follicles affected by KP were coiled.
The study's authors suggested that the circular hair shaft bursts the tissue lining the hair follicle. This causes inflammation of the hair follicle, which then triggers abnormal patterns of keratin buildup.
Despite this uncertainty, KP is not linked to any serious health concerns. KP bumps do not become cancerous. They are not contagious, and they do not typically become infected.
Left untreated, however, the bumps do tend to get worse and harder to deal with over time. Proper home management can relieve cosmetic concerns and prevent KP from worsening.
KP is a harmless condition and does not require medical treatment. As a result, it is fine for people to manage their symptoms at home. If the bumps are not bothersome, some people may be happy to do nothing at all.
Strategies for minimizing the appearance and severity of KP include:
People with dry skin are more prone to KP. Dry skin is more likely to itch, and constant scratching can irritate KP. Dry skin can also make the rough, scaly appearance of KP worse.
Trying a cream designed for very dry skin or for treating eczema may help. People should apply the cream in a thick layer after a warm shower to maximize absorption.
People with very dry skin should consider moisturizing several times a day, including any time the skin feels dry or itchy.
Avoiding dry skin
In addition to using a thick moisturizer, people should avoid using harsh soap on the affected area, or choose a moisturizing soap.
Hot showers can dry the skin, so people may want to lower the temperature of the water or only shower every second day.
Gently patting the skin dry can prevent irritation and excess dryness. People with KP may also want to consider using a humidifier at night, particularly in cold or dry climates.
Certain allergens, such as laundry detergent and cosmetics, can make KP worse.
KP is not an allergic reaction. However, people with eczema are more likely to develop it, and eczema is linked to allergies. If certain chemicals or other allergens make symptoms of eczema worse, they may also make KP worse.
Products to be wary of include:
- laundry detergent
- certain foods
People with KP should avoid products that have previously caused allergic or eczema reactions. People who are uncertain about the way their skin reacts to certain products should consider hypoallergenic skin care products and laundry detergents. These products contain substances that are less likely to cause allergic reactions.
Treating underlying skin conditions
Although anyone can develop KP, people with skin allergies and eczema are more at risk. Treating these conditions can reduce the risk of secondary conditions.
If a person develops symptoms related to another skin condition, they should see a dermatologist.
In addition to moisturizing creams, some other topical treatments can support the skin by removing dead skin cells and preventing the buildup of too much keratin.
These remedies include:
- Topical retinoids: Creams that contain retinol and other substances that come from vitamin A. These creams can help the skin produce new, healthy cells more quickly.
- Topical corticosteroids: Mild steroid creams that can reduce itching.
Exfoliating is the removal of dead skin cells from the outer surface of the skin. Removing dead skin can prevent it from becoming trapped in the hair follicle, and speed the process by which the skin gets rid of excess keratin.
Manual exfoliation, such as with a loofah or scrub, can irritate dry skin. Chemical exfoliation is less irritating and may be more successful.
Some effective chemical exfoliants include:
- salicylic acid
- lactic acid
- glycolic acid
Moisturizers containing these acids can moisturize the skin and speed the turnover of new skin cells.
When to see a doctor
Some other skin conditions, including allergic reactions and skin infections, can look a lot like KP. If symptoms get significantly worse, the skin is painful or inflamed, or home management does not work, a person should see a doctor.
Other signs that a person should see a dermatologist include:
- signs of infection, such as red streaks, skin hot to the touch, fever, or intense pain
- intense itching that is not relieved by topical creams
- KP that does not respond to home treatment
- KP accompanied by other symptoms, such as vomiting
A dermatologist can rule out other potential causes of bumpy, rough skin. If the diagnosis is KP, the doctor may prescribe a stronger chemical exfoliant or recommend corticosteroids.
The doctor might also make lifestyle recommendations, or prescribe a specific moisturizing cream.
If KP does not respond to traditional treatments, laser therapy can reduce redness and inflammation. The results are temporary, so laser treatments may have to be repeated with the next KP outbreak.