The causes and treatments of psoriasis and keratosis pilaris are different. Psoriasis may require medical attention, while keratosis pilaris usually goes away on its own.
People may confuse the two conditions, as some forms of psoriasis can have similar symptoms to keratosis pilaris. In this article, we take a closer look at these two conditions.
What are psoriasis and keratosis pilaris?
Psoriasis can cause complications, while keratosis pilaris is relatively harmless.
Psoriasis is an autoimmune disease, which is when something goes wrong with the body's immune system. Psoriasis occurs when the body produces skin cells faster than usual, causing thick, scaly patches of skin to appear.
Keratosis pilaris is a harmless skin condition. It occurs when there is a buildup of keratin in the skin. Keratin is the protein found in hair, skin, and nails.
The extra keratin builds up in the hair follicles, causing small bumps to form. The bumps are usually red, white, or skin-colored, and resemble goose bumps.
Doctors are unsure what causes the excess keratin to form. One study suggests that coiled hair shafts under the skin could be what causes keratosis pilaris.
Are psoriasis and keratosis pilaris linked?
People can have both psoriasis and keratosis pilaris, but researchers do not know whether the two skin conditions are linked.
Both psoriasis and keratosis pilaris tend to run in families. People who inherit certain genes are more likely to get psoriasis or keratosis pilaris. However, people can get either condition without having a family history.
Scientists have discovered that psoriasis usually appears after a person experiences a trigger, such as:
- skin injury, a scratch or sunburn
- some medications, such as prednisone, hydroxychloroquine, and lithium
Both psoriasis and keratosis pilaris appear in patches on the skin and can cause itchiness. Neither skin condition is contagious or infectious.
Apart from these similarities, psoriasis and keratosis are different skin conditions.
Symptoms and location of psoriasis and keratosis pilaris
Plaque psoriasis is the most common type of psoriasis. An estimated 80–90 percent of people with psoriasis will get plaques.
This table compares the symptoms of plaque psoriasis and keratosis pilaris:
|Plaque psoriasis||Keratosis pilaris|
|Can appear all over the body, but is often found on the scalp, outside of elbows, and knees||Commonly found on upper arms, thighs, and buttocks|
|Thick, raised patches of skin||Tiny bumps on the skin surface that resemble goose bumps|
|Usually red and covered with a thin, silvery-white coating known as scale||Skin-colored bumps, which may be pink, red, or white on fair skin, and brown or black on dark skin|
|Often itchy, dry, and can be painful||Can be itchy and feel rough or dry, similar to sandpaper|
|Cold or dry weather can trigger psoriasis||Keratosis pilaris is more noticeable in cold or dry weather|
|Often a lifelong condition, which can affect anyone, of any age||Commonly affects babies and young people and can disappear with treatment or as people get older|
A person with psoriasis should have a treatment plan to manage the condition.
Psoriasis is usually a lifelong condition. People with psoriasis should discuss a treatment plan with their doctor or a dermatologist who specializes in skin conditions.
What treatment a person receives for psoriasis will depend on the type and severity of their condition.
A doctor will usually prescribe topical medications for psoriasis. These may include:
- corticosteroid creams
- synthetic vitamin D
- tacrolimus ointment and pimecrolimus cream
People can use over-the-counter creams and ointments to treat mild psoriasis. These may contain:
- coal tar
- salicylic acid
- lactic acid
People can also use moisturizers to help treat their psoriasis, as these can reduce dryness and help to heal the skin.
Keratosis pilaris is completely harmless and does not require any treatment.
People may want to treat keratosis pilaris if it causes dry, itchy skin, or if they dislike the appearance.
People can use a moisturizer to help soothe the skin. Among the most effective moisturizers for keratosis pilaris are ones that contain urea or lactic acid.
Types of psoriasis
People can develop different types of psoriasis, which all have different symptoms. On the other hand, keratosis pilaris always appears as small bumps on the surface of the skin.
Sometimes, people may confuse keratosis pilaris for guttate psoriasis or pustular psoriasis, which also cause small bumps on the skin.
This type of psoriasis usually appears very suddenly and is usually linked to people having an infection, such as strep throat.
Symptoms of guttate psoriasis include:
- small, scaly bumps that form on the skin
- red to pink colored bumps
- bumps that can cover most of the torso, legs, and arms
Guttate psoriasis is usually temporary and can disappear within weeks or months without any treatment.
Pustular psoriasis causes patches of skin redness with small, pus-filled bumps. It usually appears on the hands and feet. This condition is not contagious.
These areas of skin tend to be very painful and swollen. Brown dots and scale may appear as the bumps dry out.
Severe cases of pustular psoriasis happen when pus-filled bumps cover most of the skin and break open. Medical attention is necessary in these cases, as severe pustular psoriasis can be life-threatening.
Inverse psoriasis, also called intertriginous or flexural psoriasis, develops in areas where skin touches skin, such as armpits, buttocks, and genitals.
This form of psoriasis causes smooth, painful patches of red, raw-looking skin and does not always involve a silvery-white skin coating, as in plaque psoriasis.
If people have psoriasis, they should check their fingernails and toenails for the following symptoms of nail psoriasis:
- nail coming away from the skin
- blood beneath the nail
- small dents in the nail
People with nail psoriasis should see their dermatologist for treatment, which can help prevent the condition from worsening.
A doctor may recommend a skin biopsy to diagnose psoriasis.
A dermatologist will be able to diagnose psoriasis and keratosis pilaris. They will examine the skin, scalp, and nails for any signs of psoriasis.
A dermatologist may also suggest a skin biopsy, where they remove a small sample of skin and look at it under a microscope to diagnose psoriasis.
Likewise, a dermatologist will be able to diagnose keratosis pilaris by examining the skin.
Psoriasis can increase a person's risk of developing other medical conditions. People with psoriasis can discuss this with their dermatologist, who will help assess the risks.
In contrast, keratosis pilaris has no risk factors.
- swollen or tender joints
- swollen fingers or toes
- increasing difficulty when moving
- eye problems such as conjunctivitis
- changes to their nails
When to see a doctor
If people notice symptoms of psoriasis, they should see their doctor for advice on how to manage the condition.
Keratosis pilaris is a harmless skin condition and does not require treatment. If people want to improve the appearance of keratosis pilaris for cosmetic reasons, they can see a dermatologist for advice.
Psoriasis and keratosis pilaris are both common skin conditions, which can affect a wide range of people.
Keratosis pilaris is a harmless condition that people can treat for cosmetic reasons or to soothe patches that feel dry or itchy.
People with psoriasis should see a dermatologist who will be able to create a treatment plan to manage the condition.
Are people with psoriasis more likely to get keratosis pilaris?
At this time there is no link between keratosis pilaris and psoriasis. They are two very different skin conditions. Keratosis pilaris appears when dead skin cells clog our pores, and psoriasis is when our skin overproduces skin cells. You are at a higher risk of getting keratosis pilaris if you have close relatives who have keratosis pilaris, asthma, dry skin, eczema, excess body weight, hay fever, ichthysosis vulgaris, or melanoma, and taking vemurafenib.Debra Sullivan, PhD, MSN, RN, CNE, COI Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.