Psoriasis is most common in Australasia, western Europe, and central Europe, with adult prevalence rates ranging from about 1.8% to 2.0% of the population. Globally, around 125 million people have psoriasis, representing 2 to 3 percent of the world’s population. But the disease is distributed very unevenly, with rates in some regions more than ten times higher than others.
Regions With the Highest Rates
Australasia tops the list, with an adult prevalence of roughly 2.0%. Western Europe follows closely at 1.9%, and central Europe at 1.8%. High-income North America comes in around 1.5%, and southern Latin America sits near 1.1%. Within these broad regions, certain countries stand out even further. Italy has one of the highest incidence rates in the world, with about 321 new cases per 100,000 people each year. The Scandinavian countries of Denmark, Norway, and Sweden report prevalence figures between 3.9% and 11.5%, well above the global average, likely reflecting both high diagnostic rates and population genetics.
Within the United States, psoriasis prevalence varies sharply by ethnicity. Non-Hispanic white adults have the highest rate at 3.7%, compared to 2.0% among non-Hispanic Black adults and 1.6% among Hispanic adults. Data on Asian American subpopulations remains limited.
Regions With the Lowest Rates
East Asia consistently reports the lowest psoriasis prevalence worldwide. The adult rate across the region is about 0.14%, and Taiwan holds the lowest national figure at just 0.05%. Taiwan also has one of the lowest incidence rates globally, with roughly 30 new cases per 100,000 people per year, about one-tenth of Italy’s rate. Eastern sub-Saharan Africa also reports very low numbers, around 0.15% in adults, though limited diagnostic access in the region makes that figure less certain.
Children follow a similar geographic pattern. Pediatric prevalence ranges from 0.02% in East Asia to about 0.21% in western Europe and 0.22% in Australasia.
Why Geography Matters: Genetics and Latitude
A major reason for this uneven distribution is genetic. One of the strongest genetic risk factors for psoriasis is a specific immune-system gene variant called HLA-Cw6. This variant is more common in people of European descent than in most Asian populations. Among Japanese psoriasis patients, only 10 to 12% carry it. In Chinese patients, the rate ranges from about 33 to 51%. In contrast, prevalence among Caucasian patients is generally higher, and some populations in India and South Korea show rates above 70%.
Geography plays a role beyond genetics. Countries closer to the equator tend to have lower psoriasis rates. Ultraviolet light from sun exposure is a well-established treatment for psoriasis, and populations living at higher latitudes receive less UV radiation year-round. Systematic reviews have found robust associations between autoimmune disease prevalence (including psoriasis) and both latitude and average annual temperatures. This helps explain why Scandinavian countries, which sit far from the equator, have some of the highest rates in the world.
Some Populations Appear Nearly Unaffected
Indigenous populations in the Andean region of South America appear to have almost no psoriasis at all. This observation has led researchers to hypothesize that the disease may have been introduced to the Americas during European colonization. The near-absence of psoriasis among Quechua and Aymara communities in Peru supports the idea that certain genetic backgrounds confer strong protection against the disease. When psoriasis does occur in these populations, however, a small Peruvian study found it tends to be more severe and longer-lasting.
The Global Burden Is Growing
Psoriasis is becoming more common worldwide. Between 1990 and 2021, the total number of people living with psoriasis nearly doubled, rising from about 23 million to 43 million. New cases per year grew by 80% over the same period, from 2.85 million to 5.1 million. The increase is concentrated in high-income regions with aging populations and greater healthcare access, including western Europe and North America.
That last point highlights an important caveat in the data. Reported prevalence depends heavily on whether people have access to a doctor who can diagnose psoriasis. In many low-income regions, particularly in sub-Saharan Africa and parts of South Asia, considerable data gaps remain. The Global Psoriasis Atlas notes that for countries without high-quality original data, estimates are predicted using statistical models rather than direct measurement. This means that low reported rates in developing regions may partly reflect underdiagnosis rather than true absence of the disease.