What Is Psoriasis?

Psoriasis is a chronic inflammatory skin condition. Symptoms often include red patches of skin covered by scales, or dead skin. These patches are also called psoriatic plaques. In some cases, fingernails and toenails are affected, causing a lifting, pitting, discoloration and crumbling of the nail.

Psoriatic plaques may only cover a small area of skin. In severe cases of psoriasis, symptoms may cover larger areas of skin.

Physicians may sometimes define mild psoriasis as involving about 2% of skin area, which is about the size of the palms of both hands. They may determine that moderate psoriasis is occurring if symptoms cover about 3% to 10% of skin. Severe psoriasis involves more than 10% of skin area. Often psoriasis amounts to a minor irritation of the skin, but it can also be quite painful and disabling for some people.

Psoriasis is referred to as an “immune-mediated” condition. This means the immune system may be malfunctioning, causing the body to accelerate the growth of skin cells at a faster pace than usual. In skin that is not affected by psoriasis, the cells mature and reach the skin’s surface every 28 to 30 days. In psoriatic skin, skin cells mature more rapidly, within about 3 to 6 days. As a result, the overproduction of skin cells forces them to pile up on the skin, causing psoriatic symptoms such as plaques and lesions.

People with psoriasis may not have symptoms all the time. The disease can go into remission and the skin will remain clear for some time. Other times, psoriasis may occur in cycles or during a certain time of year, such as winter when many people with the condition say it worsens.

What happens to the skin and why?

Research has indicated that psoriasis is an immune-mediated disease. This means the immune system, which is responsible for protecting the body against disease and infection, may not be working properly. Rather than focusing on invading foreign organisms, the immune system targets healthy skin cells. As a result, a condition such as psoriasis can develop.

The first appearance of psoriasis may, according to some research, be triggered by something. Possible triggers include stress, skin injuries, medications, respiratory or throat infections, or severe sunburn. Although this is not always the case, if a person already has a family history of psoriasis, one of these triggers may cause psoriasis to occur.

Psoriasis develops when the ordinary life cycle of the skin accelerates. In skin that is not affected by psoriasis, the cells mature and rise to the skin’s surface over a period of 28 to 30 days. This is ample time for dead skin cells to flake off or shed as new cells mature and reach the skin’s surface.

When skin is affected by psoriasis, the time it takes for a skin cell to mature and surface is much shorter, about 3 to 6 days. Because of this, the abundance of dead skin cells pile up and form scales or lesions. These scales are often accompanied by red itchy patches, or plaques. The skin becomes inflamed in the affected area and can shed, crack, or bleed.

Who gets psoriasis?

People with psoriasis are frequently diagnosed at an early age, usually between ages 15 and 35. About three-quarters of people with psoriasis will be diagnosed before age 40. Occasionally, psoriasis appears in childhood. This is referred to as juvenile psoriasis.

Approximately 4.5 million people in the U.S. have been diagnosed with psoriasis. Psoriasis affects men and women equally, but research has suggested that ethnicity may be a factor. Psoriasis is more common among Caucasians of northern European descent than among Africans or Asians.

Genetics may also play a part in who gets psoriasis. About a third of people who have psoriasis have a family history of the disease. However, there is no guarantee that a person will develop psoriasis just because a family member has the disease. Certain things may need to happen in the body in order to trigger the onset of psoriasis. Medications, skin injuries, respiratory infection, stress, or severe sunburn may trigger the occurrence of psoriasis.

You can’t catch psoriasis.

It is important to know that psoriasis is not contagious. It is not a virus or a germ. You cannot “catch” it from someone. This misconception about psoriasis exists because plaques or lesions can resemble infected skin. However, contact with psoriasis does not result in transmission of the disease. Psoriasis is a disease that may likely be caused by a number of internal factors, including genetics, ethnicity, and immune system malfunction.

Next: Diagnosing Psoriasis