Psoriasis
Psoriasis
Psoriasis is a chronic autoimmune condition that affects the skin and, in many cases, other parts of the body. It occurs when the immune system sends faulty signals to the skin, causing skin cells to grow much faster than normal. Typically, skin cells take about 28 days to form and shed, but in psoriasis this process can happen in just 3 to 7 days. Because the body cannot shed these cells quickly enough, they build up into thick, scaly patches called plaques. These plaques are often red, inflamed, and itchy. Although psoriasis affects the skin, it is not a contagious condition—it cannot be spread by touch.
Prevalence and Global Burden
Psoriasis is one of the most common immune-mediated diseases worldwide. It affects about 2–3% of the global population, which equals roughly 125 million people (National Psoriasis Foundation, 2023). In the United States, about 7.5 to 8 million people live with psoriasis, representing around 3% of the adult population. Rates differ between groups: approximately 3.6% of White adults, 2.5% of Asian adults, 1.9% of Hispanic adults, and 1.5% of Black adults are affected (National Psoriasis Foundation, 2023). Psoriasis also tends to be more common in middle-aged and older adults, with the highest prevalence—about 4.3%—seen in people between 50 and 59 years old.
Across the world, the frequency of psoriasis varies widely. In Taiwan, only about 23 out of every 100,000 people are newly diagnosed each year, while in Italy that number is over 320 per 100,000 (Parisi et al., 2023). Prevalence is as low as 0.14% in East Asia but can reach almost 2% in Australasia (Global Psoriasis Atlas, 2023). Unfortunately, about three-quarters of countries still lack reliable data, which means the true global burden could be even higher.
The impact of psoriasis has grown significantly over time. From 1990 to 2021, the number of people living with psoriasis rose from about 23 million to 43 million, an 86% increase (Zhang et al., 2023). During the same period, disability-adjusted life years (DALYs)—a measure of how many healthy years are lost due to disease—increased by 85%. This shows that psoriasis is not only more common today but also a greater public health challenge.
Types of Psoriasis and Related Conditions
There are several types of psoriasis, though plaque psoriasis is the most common, accounting for 80–90% of all cases (Healthline, 2023). Other forms include scalp psoriasis, which affects almost half of patients, nail psoriasis that occurs in about 50%, guttate psoriasis seen in 8%, inverse psoriasis affecting 21–30%, pustular psoriasis in 3%, and erythrodermic psoriasis in 2%.
Psoriasis is more than just a skin disease. About one-third of people with psoriasis develop psoriatic arthritis, an inflammatory joint condition that can cause pain, stiffness, and long-term damage (National Psoriasis Foundation, 2023). In addition, psoriasis is linked with other serious health problems, such as cardiovascular disease, type 2 diabetes, depression, and inflammatory bowel disease (American Academy of Dermatology, 2023). These connections highlight the fact that psoriasis is a systemic disease—it affects the whole body, not just the skin.
Diagnosis and Treatment
Psoriasis is usually diagnosed through a physical examination by a healthcare professional, since the plaques are often recognizable. In unclear cases, a skin biopsy may be performed to confirm the diagnosis and rule out other conditions.
Treatment depends on how severe the condition is. For mild psoriasis, topical creams or ointments—such as corticosteroids or vitamin D analogues—are often effective. In fact, around 75% of patients with mild cases improve significantly with topical treatments alone (Wikipedia, 2025). For moderate to severe psoriasis, other options include phototherapy (controlled exposure to ultraviolet light) and systemic medications. These systemic treatments can be taken orally or by injection and include methotrexate, cyclosporine, and newer biologic drugs that specifically target the immune system. While no cure exists, these treatments can reduce symptoms, control flare-ups, and greatly improve quality of life.
Current Trends and Outlook
Although treatment options have improved dramatically, the global burden of psoriasis continues to rise. In high-income countries especially, both the number of cases and the severity of disease have increased over the past decade (Zhang et al., 2023). Looking ahead, researchers predict that while the number of new cases may remain steady in younger people, it could increase slightly among older adults as life expectancy rises. At the same time, the number of years lost to disability (DALYs) is expected to decline, thanks to better access to effective therapies (Li et al., 2024).
Conclusion
Psoriasis affects between 2 and 3% of people worldwide, including nearly 8 million Americans. Plaque psoriasis makes up almost 90% of cases, and about one in three patients also develop psoriatic arthritis. Prevalence is highest among White adults and in middle age, but all racial and age groups can be affected. Since 1990, the global number of psoriasis cases has nearly doubled, and disability related to the condition has increased by more than 80%. These statistics demonstrate that psoriasis is not simply a cosmetic issue but a major health concern with serious physical and emotional consequences.
While psoriasis cannot yet be cured, advances in topical treatments, phototherapy, and systemic biologics have given patients more options than ever before. Because psoriasis often overlaps with other conditions such as heart disease and depression, comprehensive care that addresses both physical and mental health is essential. With continued research, early diagnosis, and access to modern therapies, the outlook for people living with psoriasis continues to improve, even as the disease remains a significant global health challenge.
References
American Academy of Dermatology. (2023). Psoriasis: Statistics. Retrieved from https://www.aad.org/media/stats/conditions/psoriasis
Global Psoriasis Atlas. (2023). Global epidemiology of psoriasis. Retrieved from https://www.globalpsoriasisatlas.org
Healthline. (2023). Psoriasis facts and statistics. Retrieved from https://www.healthline.com/health/psoriasis/facts-statistics-infographic
Li, X., Wang, Y., & Chen, J. (2024). Forecasting psoriasis incidence and disability-adjusted life years from 2025 to 2035. Chinese Annals of Medicine and Health Economics, 41(2), 134–142.
National Psoriasis Foundation. (2023). Psoriasis statistics. Retrieved from https://www.psoriasis.org/psoriasis-statistics
Parisi, R., Iskandar, I., Griffiths, C., & Ashcroft, D. (2023). Global variation in psoriasis incidence: findings from the Global Psoriasis Atlas. British Journal of Dermatology, 191(S3), 61–72.
Wikipedia. (2025). Psoriasis. Retrieved from https://en.wikipedia.org/wiki/Psoriasis
Zhang, Y., Chen, R., & Li, M. (2023). Global burden of psoriasis from 1990 to 2021: Results from the Global Burden of Disease Study. Rare Disease Advisor. Retrieved from https://www.rarediseaseadvisor.com