Psoriasis-Basic Statistics

How common is psoriasis?

Although it is difficult to estimate exactly how many people are living with psoriasis, it is thought that the disease affects at least 125 million people around the world. This means that about 2%-3% of the global population have some form of psoriasis.1,2,3,4

Researchers have conducted large surveys in the United States in order to estimate how many people in the country have psoriasis. The results of the surveys suggest that around 3% of adults over the age of 20 in the US have been diagnosed with psoriasis. This means that at least 7 million adults in the United States are living with the disease. Each year, around 150,000 people are newly diagnosed with psoriasis.

However, researchers think that it is likely that many more than 7 million people in the United States have the disease. This is because many people may not have been diagnosed by a healthcare provider yet, or do not know for sure that they have psoriasis. Other people may have been misdiagnosed with some other disease when they actually have psoriasis, because the symptoms of psoriasis are similar to those caused by other skin conditions. Some researchers think that up to 3.5 million people may be living with undiagnosed psoriasis in the United States.

Are some people more likely than others to develop psoriasis?

People of all ages can develop psoriasis. Around one-third of people with psoriasis are diagnosed with the disease before the age of 20, and around three-quarters of people are diagnosed before the age of 40. Some people who have never had the condition before will develop it for the first time between the ages of 50 and 60.2 Unlike some other diseases, psoriasis affects men and women at equal rates.

Psoriasis is less common among children than among adults, and it is relatively rare among infants. Around 10% to 15% of people with psoriasis are diagnosed before the age of 10.4 However, children who have family members with psoriasis are more likely to develop the condition than children who do not. Researchers estimate that a child has about a 50% chance of developing psoriasis if both parents have the condition and around a 10% chance if one parent has the condition.

Psoriasis can affect people of all ethnicities. In the United States, research has shown that psoriasis is more common among people of certain ethnicities than others. For example, researchers estimate that in the United States, around 3.6% of Caucasians have psoriasis compared to around 1.9% of African-Americans.5 In people with darker skin tones, however, psoriasis skin lesions may appear with a more purplish hue. 

What types of psoriasis are the most common?

Plaque psoriasis is the most common type of the disease: about 80% to 90% of people with psoriasis have this type. The next most common type is guttate psoriasis, affecting around 18% of people with the disease.2 This type is more common among children and younger adults.

The other three types of psoriasis are much less common, with each affecting around 2% or less of people with psoriasis. Pustular psoriasis, a very severe type, is more common among older people than younger people. Inverse psoriasis tends to affect the skin folds, while psoriatic erythroderma is a very severe form of the disease that affects more than 90% of the body.

About 30% of people with psoriasis will also be diagnosed with a related condition called psoriatic arthritis at some point during their lives. People of any age can develop psoriatic arthritis, although it most commonly occurs between the ages of 30 and 50.5 For most people who go on to develop psoriatic arthritis, their diagnoses often is delayed about a decade after they’ve been diagnosed with psoriasis.

Research suggests that around 80% of people with psoriasis in the United States have a mild form of the disease. This means that the disease affects 3% or less of their bodies. Around 20% of people in the United States have moderate disease (which affects between 3%-10% of the body) or severe disease (which affects more than 10% of the bodies.6

What are the financial costs of psoriasis?

Because psoriasis is a condition that affects so many Americans, it has a large financial impact on the health system in the United States. Researchers think that it may cost the United States many billions of dollars every year.

Living with psoriasis can also impact a person’s ability to work and earn money. It can cause a person to miss work due to the disease, or it can affect productivity when a person goes to work when they are affected by their symptoms. One study found that around 20% of people with psoriasis missed work due to the disease, while around one-third of people went to work despite feeling unwell due to symptoms related to psoriasis.7

Written by: Anna Nicholson | Last reviewed: July 2016.
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