This article discusses how common psoriasis is and other demographics.

How Many People Have Psoriasis?

According to the National Psoriasis Foundation, more than 8 million people in the United States have psoriasis. About 2%–3% of the world’s population has it. This equals 125 million people.

Experts consider psoriasis to be a common skin condition, affecting all races, but it is most prevalent among White people.

Where Is Psoriasis Most Common?

Psoriasis appears to be most common in the northern countries of Europe. Norway has the highest number of people with psoriasis, and East Asia has the lowest.

The United States is among the countries with a higher prevalence of psoriasis. There is evidence that psoriasis is on the rise around the world.

What Causes Psoriasis?

Experts don’t know exactly what causes psoriasis. It is an autoimmune condition, in which the immune system—which typically defends the body from infection—overreacts, causing certain white blood cells to become overactive. As a result, these cells cause inflammation, and they divide more quickly than usual and develop abnormally.

Psoriasis tends to run in families, but it can occur in people who have no relatives with psoriasis. The rashes and scaling tend to come in flares (times when symptoms worsen), which can be triggered by stress, cold or dry weather, injury, and infection, among other factors.

How Is Psoriasis Diagnosed?

A dermatologist (skin specialist) can usually diagnose psoriasis by looking at your skin and asking you about your symptoms.

Psoriasis symptoms can be similar to eczema (atopic dermatitis), so your dermatologist or other healthcare provider may order a laboratory test to analyze a small sample of your skin to confirm the diagnosis.

Treatment for psoriasis and eczema differs, so it’s important to have an accurate diagnosis.

What Is the Life Expectancy for People with Psoriasis?

Mild psoriasis does not seem to affect life expectancy. However, people with severe psoriasis may have a somewhat shorter life span by about three or four years due to complications. But each case is different, and statistics don’t represent individual outcomes.

People with psoriasis may be more likely to develop some serious health conditions, which can affect longevity. These include heart disease, kidney disease, dementia, and infection.

When to See a Healthcare Provider

If you see red patches that are covered with white flaky skin that itch or feel sore, contact a dermatologist or healthcare provider, who can examine you for psoriasis. If you have dark skin, the areas may look more purple, gray, or darker brown.

Psoriasis can become more severe over time or lead to psoriatic arthritis, which should be treated to minimize any damage to your joints.

Your provider can also talk to you about topical treatments or other medications or injections to alleviate the itching and rashes, and help you learn to identify triggers so you can minimize psoriasis flares.

Summary

Psoriasis is a skin condition caused by an immune system overreaction that leads to itchy, sore patches on the skin that are covered in gray or white scales. It affects about 8 million people in the United States and 2%–3% of the population globally.

Psoriasis can be mild or severe. Severe psoriasis is linked with some serious health conditions, such as heart disease and psoriatic arthritis. If you think you may have psoriasis, see a dermatologist.

A Word From Verywell

People with psoriasis often feel self-conscious about their skin. But psoriasis is, in fact, fairly common, so you’re not alone. Psoriasis treatments have improved over time, and your provider can help get your psoriasis under control or in remission.