Psoriasis is a chronic skin condition. It causes red patches of thick, flaky silvery-white scales that may itch. The patches usually develop on the scalp, elbows, knees, and other areas. They may scab over.


There are different types of psoriasis. The most common is plaque psoriasis. Other types include pustular psoriasis (pudding-like bumps filled with pus), and sebopsoriasis (changes to the skin’s surface, including greasy patches). You can also have psoriatic arthritis, which is stiff, painful joints.


Psoriasis is a long-term (chronic) disease that causes red, scaly patches to appear on the skin. These patches can be itchy and sore, and they may bleed and crack. Most people with psoriasis also have stiff and sore joints (psoriatic arthritis). Psoriasis usually starts before age 45. It goes through cycles, with symptoms flaring for a few weeks or months and then subsiding or going into remission.

The cause of psoriasis isn’t known, but it has to do with how your immune system works. Your immune system is supposed to destroy bacteria and other foreign invaders that can make you sick. But with psoriasis, your immune system gets overactive and speeds up the growth of new skin cells. The fast-growing skin cells build up on the surface of your skin and form thick, scaly lesions.

Symptoms often develop on the knees, elbows, and scalp, but they can appear anywhere on your body. These dry, raised, scaly patches are called plaques. Some types of psoriasis affect the nails, causing them to become brittle and red or to have dents in them. Psoriasis can be very itchy, and it’s common to scratch your rash, but you should not do this because it makes the plaques worse. If you scratch, you can break the skin and get an infection. Psoriasis can lead to other health problems, including psoriatic arthritis and heart disease.


Psoriasis usually appears as raised, red patches of skin covered with silvery scales. These thick, itchy patches may cover large areas of the body or small parts, such as the scalp, knees, elbows, and lower back. They can also occur on the fingernails and toenails, and in the joints (psoriatic arthritis). People with psoriasis are at increased risk for inflammatory types of arthritis such as rheumatoid arthritis, osteoarthritis, and gout.

Your doctor will ask questions about your symptoms and examine the affected areas of your skin. They will use a device called a PASI scale to measure how severe your symptoms are and grade your psoriasis.

You might need a skin biopsy to confirm the diagnosis of psoriasis, especially if your symptoms are unusual or severe. Your doctor will inject the area with a local anesthetic before taking the tissue. They will then send the sample to a lab to be examined under a microscope.

Your doctor can prescribe medications to reduce your symptoms and the severity of psoriasis. These include creams, ointments, or lotions that contain corticosteroids, vitamin D, retinoids (related to vitamin A), coal tar, or other substances. They might also recommend phototherapy, which involves being exposed to ultraviolet A or ultraviolet B light. Some types of psoriasis respond better to light therapy than others.


Treatments can improve the appearance of skin patches and reduce itching. The first treatments your doctor might try are creams and ointments that are applied to the skin (topical therapy). Your doctor may also want to look at a small sample of your skin (biopsy) for more information about the type of psoriasis you have.

The most common form of psoriasis is plaque psoriasis. The most characteristic feature of this form is red and silvery scales that build up in thick patches over the elbows, knees, scalp, genitals, or back. These patches are often itchy and sore, and they can crack and bleed. Some people have a severe version of this condition that covers the whole body. In addition, some people get a form of arthritis called psoriatic arthritis that causes stiff, painful joints.

In general, psoriasis occurs when your immune system mistakes the cells that grow deep in your skin for invading bacteria and attacks them. This speeds up the process of making new skin cells and pushes them to the surface too fast. They then form the thick, red, scaly patches of psoriasis that can be itchy and sore. The treatment options for psoriasis include topical treatments, light therapies, and medications taken by mouth or injected. People with psoriasis should have regular blood and liver function tests to check for side effects, especially before starting new medicines or stopping old ones.


Psoriasis is an autoimmune disease. That means it occurs when your immune system becomes overactive and attacks healthy skin cells instead of attacking foreign invaders like bacteria. Your over-reactive immune system creates thick, scaly patches of skin that usually appear on the knees, elbows or scalp, although they can be anywhere on your body. They may also itch and scale. The cause of psoriasis is not known, but genetics plays an important role. People who have a family member with psoriasis are more likely to get it themselves.

Your doctor can prescribe medicine to control your psoriasis symptoms. This medicine can be creams, ointments, tablets or foams that are applied to the skin or taken by mouth. You can also use a moisturizer to keep your skin hydrated.

Itching can make psoriasis worse, so it’s important to not scratch your skin. If you must, apply a nonprescription anti-itch cream or ointment. Also, keep your nails trimmed so they don’t rub against the affected area and wear soft fabrics that won’t irritate your skin.

A nutrient-rich diet can help manage your symptoms. Talk to your doctor about eating a variety of foods including fruits, vegetables, whole grains, fish and lean meats. Also, losing excess weight can help reduce your symptoms. Alcohol can trigger psoriasis in some people, so reducing or eliminating it from your diet is a good idea.