Psoriasis is a chronic skin disease that causes painful and unsightly patches. Psoriasis is also an autoimmune disease, which means that when the immune system becomes overactive, skin cells develop too quickly, causing scaly patches to form.

Psoriasis is not contagious, due to poor hygiene, or caused by skin irritation. So the right soap will not prevent psoriasis or wash the patches away. The right soap can, however, prevent patches from getting worse and help healthy skin grow more quickly.

Types of soap for psoriasis

A person who has psoriasis and very dry skin may benefit from a moisturizing soap. A dermatologist can help with picking the right soap. Some options that may help include:

Tar soaps
Tar soaps, made from either coal tar or wood tar, may help to ease the symptoms of psoriasis, although they can make the skin more vulnerable to sunburn.

Some studies have found that tar can help slow the growth of skin cells that contribute to psoriasis plaques. Tar can also help with:

• itching
• redness
• inflammation

Tar soaps come in two varieties: coal tar and wood tar. Wood tar soaps are made from the wood of a variety of plants, such as juniper and pine. Coal tar has been more thoroughly studied for the treatment of psoriasis.

Doctors are unsure precisely how tar soaps work or why they work. Yet, studies continue to show that tar soaps can help with psoriasis.

A 2010 analysis of explored data from 25 previous studies of coal-tar soap used to treat psoriasis noted that 84 percent of the studies found that coal-tar soap was effective. In 16 percent of the studies, data showed no benefit to using coal tar soap.

Tar soap has a strong unpleasant odor and makes the skin more vulnerable to sunburn. In some people, sunburn is a risk factor for psoriasis outbreaks, so people who use tar soap must wear sunscreen.

Some people experience skin irritation or burning with tar or tar soap. Test a small patch of skin before using the soap on large portions of the skin.

Some studies suggest shampoos and other products with high concentrations of coal tar may increase the risk of cancer. In California, products containing more than 0.5 percent coal tar must carry a cancer warning.

The U.S. Food and Drug Administration (FDA) say coal tar concentrations between 0.5 and 5 percent are safe. A 2010 study that included 13,200 people found no increase in cancer risk among people who used coal tar products for 1 to 300 months.

Exfoliating soaps

Exfoliating soaps help lift the top layer of skin. This can help speed up the healing process, allowing the body to replace scaly patches with smooth, healthy skin more quickly.

Salicylic acid is one of the most popular and safest exfoliating ingredients. Many acids, including glycolic acid and lactic acid, can also exfoliate the skin.

Stronger exfoliating soaps may qualify as keratolytics. A keratolytic is a treatment that helps remove psoriasis scales.

This can speed healing and allow psoriasis medications to penetrate deeper into the skin. These products can be highly irritating and might not be safe to use on all areas of the body.

Talk to a doctor before using a highly concentrated exfoliating soap. Always do a patch test on a small patch of skin before using the product.

Pregnant women should not use chemical exfoliators without first talking to a doctor. Salicylic acid and some other acids can harm a developing fetus.

Oatmeal soap

Oatmeal soap, particularly colloidal oatmeal, can ease the pain and itching associated with psoriasis. It may also help reduce the redness of psoriasis patches. Research has found that oatmeal can reduce inflammation and may even prevent the skin from releasing chemicals that promote inflammation.

Oatmeal products are unlikely to irritate the skin, even in people with a history of allergic reactions. So for psoriasis sufferers with sensitive skin or who cannot use other products, oatmeal soap may be a good option.

Moisturizing soap

Dry skin does not cause psoriasis. However, dry skin may be itchy and irritated, making the pain of psoriasis worse. A variety of oils and moisturizers may help. Some people with psoriasis prefer to use soaps containing natural oils, such as aloe or avocado oil, to avoid allergic reactions and chemical irritation.

What is the difference between psoriasis soap and lotion?

Soaps are not the only way to improve the health of the skin. A variety of lotions can also help. Many psoriasis lotions contain the same ingredients as psoriasis soaps.

Some manufacturers offer salicylic acid solutions to leave on the skin, and many produce oatmeal-based lotions.

The primary difference between psoriasis lotions and soaps is that lotions are safe to leave on the skin. In fact, many have to stay on the skin to work.

For example, hydrocortisone is a steroid that can reduce itching and skin irritation. Hydrocortisone lotions need to remain on the skin to work well.

Because lotions are safe to leave on the skin, they are usually less potent than soaps that contain the same ingredients. For example, salicylic acid soaps tend to be stronger than salicylic acid lotions.

It is important to follow the label instructions to avoid skin irritation. Do not leave psoriasis soap on the skin.

People with psoriasis who use both lotions and soaps should be careful with ingredients that are known to irritate skin.

Use only an exfoliating soap or lotion, not both. Sometimes products behave differently when mixed. Perform a patch test of the lotion and soap together before using them all over the body.

Psoriasis outlook and help

Psoriasis is a chronic condition that no soap will permanently cure. People with psoriasis should seek medical treatment rather than just relying on home remedies. These treatments can address the underlying cause of psoriasis, improving the skin’s appearance and reducing the frequency of outbreaks.

Psoriasis soaps and other home remedies can work together with medical treatments to produce longer periods of clear, scale-free skin.