People with dry skin conditions, such as psoriasis, generally have low amounts of a natural skin moisturizer called urea. Topical, over-the-counter (OTC) products called keratolytics may contain urea and can be useful in treating dry skin conditions.
Urea is an organic compound that is naturally present in healthy skin. It is one of three natural moisturizing factors in the horny outer layer of the skin, along with amino acids and lactic acids. People with dry skin conditions such as psoriasis have markedly reduced amounts of urea.
Psoriasis is a chronic autoimmune condition. It is caused by malfunctioning white blood cells, which attack the skin cells and cause them to grow far more rapidly than normal. Instead of shedding normally, the skin cells build up on each other, causing itchy, painful plaques to form.
Psoriasis can cause irritation anywhere on the skin, but scales and rashes most commonly occur on the knees, elbows and scalp. The rashes appear red on white skin, and gray, violet or darker brown on skin of color.
Psoriasis is associated with certain other conditions. People who have psoriasis are more likely to also have:
- psoriatic arthritis
- inflammatory bowel disease such as Crohn’s disease
- uveitis, an inflammation of the eye
- celiac disease
- palmoplantar pustulosis
- metabolic syndrome
Products that contain keratolytics may help ease psoriasis symptoms by softening psoriasis patches, reducing itching, and speeding healing time. Urea is an OTC keratolytic product, along with salicylic acid and phenol.
Urea preparations are emollients, which means they reduce water loss from the upper layer of skin, called the epidermis, making skin more supple and moisturized. People can get some urea products as OTC medications. They may need a prescription for products with certain ingredients, such as strong corticosteroids.
Urea can help ease psoriasis in several ways, including:
- Soothing: It acts as a local anesthetic and soothes irritation on the skin.
- Hydrating: It draws water and retains it within skin cells, in a process called a hygroscopic effect.
- Regenerative: It can help improve the skin’s ability to repair itself, while also protecting against dryness.
- Keratolytic: It can soften the horny outer layer of skin, making it easier to remove.
- Improved absorption: It can help other substances, such as corticosteroids, penetrate better into the skin.
- Occlusive film: As an emollient, urea gel also works by generating an occlusive, or water and airtight, film on the skin. This reduces the amount of water lost from evaporation and helps the skin stay hydrated.
Other topical treatments
There are various other treatments for psoriasis, including prescribed and OTC topical medications, biologics, and therapies. A person may also consider lifestyles changes, including diet.
A doctor or dermatologist can advise on the best options, depending on where rashes are on the body and the severity of the condition.
OTC medicine
Non-prescription, OTC medicines can be beneficial to people with mild psoriasis. They include:
- Hydrocortisone: This mild corticosteroid is often found in creams and ointments, and may help reduce inflammation and itching.
- Coal tar: This ingredient can be found in some prescription and OTC medications. It may help reduce flaking, itching, overproduction of skin cells, and scaling.
- Scale softeners: Products containing urea, lactic acid, and salicylic acid may help soften scales.
- Anti-itch: Some products may help reduce itching from psoriasis. The products may contain ingredients such as camphor, calamine, and menthol.
Prescription medicines
A doctor or dermatologist may prescribe certain medicines for psoriasis. These may include:
- methotrexate, which suppresses the overactive immune system.
- apremilast, which may reduce scales and redness by decreasing inflammation.
- oral retinoids, which can help reduce swelling and redness, and stop the overproduction of skin cells.
Biologics
Biologics target the specific part of the immune system that is overactive in people with psoriasis. A doctor can give biologics intravenously through a drip, or via injection.
Phototherapy
This process involves a doctor or dermatologist placing a certain type of UV light on the affected areas of a person’s skin. It can help slow the growth of skin cells, suppress the overactive immune system, and reduce itching and inflammation.
Diet
A diet of anti-inflammatory foods may help reduce the symptoms of psoriasis. These foods include beans, oily fish, fruits and vegetables, and nuts and seeds.
There are different types of psoriasis, including the most common ones such as plaque and inverse psoriasis, and rare types such as guttate, pustular, and erythrodermic. A person can develop more than one type of psoriasis.
Plaque psoriasis
This is the most common type of psoriasis and affects up to 80% of people who have the condition.
Plaque psoriasis causes silvery, scaly plaques to develop on the skin. They can appear anywhere on the skin, and are accompanied by a red, brown, gray or violet rash, depending on a person’s skin color. The plaques are often painful or itchy.
Inverse psoriasis
Inverse psoriasis is also fairly common, and affects about 25% of people with psoriasis. It typically causes deep reddening of the skin in areas where the skin folds, such as under the breast and arms and in the genital area. It does not cause scaly plaques, but is usually painful and itchy.
Guttate psoriasis
Guttate psoriasis affects about 8% of people with the condition. It appears as small, round, red spots.
Pustular psoriasis
Pustular psoriasis is rare, and affects around 3% of people with psoriasis. It presents as pus-filled, white bumps on reddened, inflamed skin. It may occur across the entire body, or in certain areas such as the feet or hands.
Erythrodermic psoriasis
Erythrodermic psoriasis is rare, affecting around 2% of people who have psoriasis.
The condition can be life-threatening and includes symptoms such as shedding skin in sheets, dehydration, severe pain and itching, and intense redness.
Inflammation is the basic cause of psoriasis symptoms, which may flare, subside, or disappear at different times. Symptoms may be different from one person to another, and may include:
- cracked, itching, or bleeding skin
- skin that is violet, dark brown, gray, or red, depending on a person’s natural skin color
- ridged, thickened nails
- silvery scales that burn and itch
Experts do not completely
Immune system
A malfunctioning immune system can cause psoriasis. While blood cells attack bacteria and viruses in the body when they are functioning normally, they can attack skin cells when they malfunction.
This malfunction can cause the body to rapidly produce new skin cells, which pile on top of each other on the skin’s surface. This causes the change in skin color and the rashes and scales associated with psoriasis.
Family history
If a person has a close family member such as a sibling, parent, or grandparent with psoriasis, they are at a higher risk of developing the condition.
Triggers
Certain things may trigger psoriasis, either as a flare-up in someone who has experienced it before, or for the first time. Common triggers include:
- stress
- dry, cold weather
- skin injury, such as severe sunburn
- excessive alcohol consumption
- tobacco use
- certain medications, including lithium and hydroxychloroquine
- some infections, such as strep throat
A dermatologist or doctor can diagnose psoriasis by physically examining the skin, scalp, and nails for signs of the condition. They may also take a skin biopsy in order to closely examine the skin.
Psoriasis is a chronic autoimmune condition. A doctor or dermatologist can treat it using urea products such as those in a topical preparation, other topical medicines, prescription medicines, biologics, or phototherapy. Products containing urea can be effective for people with psoriasis.
The different types of psoriasis include plaque, inverse, guttate, pustular, and erythrodermic, with symptoms including inflamed, dry skin with red, dark brown, violet or gray patches, and silvery scales.
Psoriasis may be caused by a malfunction in the immune system, and a family history of the condition makes a person more likely to develop it themselves. Certain triggers may bring it on for the first time or cause it to flare. A doctor or dermatologist will diagnose psoriasis by examining the skin and possibly performing a biopsy on the skin.