Global Burden of Psoriasis from 1990 to 2021 and Potential Factors: A Systematic Analysis

Psoriasis is a chronic, immune-mediated inflammatory skin disorder affecting approximately 100 million people worldwide. This study aimed to understand the global impact of psoriasis on health and economics over the past 3 decades. We analyzed trends in psoriasis cases, its effects on people's QOL, and the associated costs. We found that the number of people living with psoriasis nearly doubled from 1990 to 2021, reaching 43 million cases globally, with 5.1 million new cases diagnosed in 2021 alone. The Bayesian age-period-cohort model forecasts a continued upward trend in global psoriasis burden from 2022 to 2040. The condition was most common in people aged 50-70 years, and the highest rates of new cases occurred in East Asia. Psoriasis was significantly linked to risk factors such as obesity, lack of physical activity, air pollution, and UV radiation. The economic burden of psoriasis in 2021 reached $148.85 billion, including $95.15 billion in healthcare costs and $53.70 billion in productivity losses. High-income countries bore most of the costs, whereas lower-income countries experienced a greater proportion of productivity losses. These findings highlight the increasing global burden of psoriasis and the need for targeted strategies to address its risk factors and reduce healthcare inequalities.