Systematic Review Examining Changes Over Time and Variation in the Incidence and Prevalence of Psoriasis by Age and Gender

I.Y.K. Iskandar; R. Parisi; C.E.M. Griffiths; D.M. Ashcroft


The British Journal of Dermatology. 2021;184(2):243-258. 

In This Article

Abstract and Introduction


Background: There is a lack of any overview of changes over time and variation in the epidemiology of psoriasis with age and between genders.

Objectives: To perform a systematic review of published population-based studies on variations in psoriasis incidence and prevalence with age and between genders, and to explore trends in psoriasis epidemiology over time.

Methods: Eleven electronic and regional databases were searched from their inception dates to October 2019. No language restrictions were applied. Studies were eligible if they reported on changes in psoriasis incidence and/or prevalence over time and/or by age group and gender.

Results: In total 308 papers were critically appraised, from which 90 studies from 22 countries were included. Incidence data confirmed a clear bimodal age pattern in psoriasis onset, with the first and second peaks at around 30–39 and 60–69 years of age, respectively, and evidence suggesting that it presents slightly earlier in women than in men. Prevalence data showed an increasing trend with age until around 60 or 70 years, after which it decreases. Although there was lack of agreement on specific gender differences in psoriasis incidence and prevalence, a slight male predominance was reported in several studies. Studies worldwide suggested a stable or slightly decreasing trend in psoriasis incidence, while an increasing trend in psoriasis prevalence has been consistently reported. One particular challenge faced was the vastly different methodologies used in the included studies, which contributed to some of the heterogeneity of the results.

Conclusions: Studies on changes over time in the occurrence of psoriasis have contributed to a greater appreciation of the increasing burden of the disease. However, further research is required to determine the reasons driving the increase in psoriasis prevalence over time.


Psoriasis has been recognized by the World Health Organization as a serious, disfiguring, disabling, noncommunicable disease that represents a significant public health challenge due to its psychological, social and economic burden.[1] In 2016, the World Health Organization emphasized the need to understand better the global epidemiology of psoriasis so as to inform policymakers and healthcare professionals on the public health impact of the disease.[1]

The Global Psoriasis Atlas (GPA) aims to improve the understanding of psoriasis epidemiology and its comorbidities, and to provide a common benchmark on the global burden of psoriasis.[2] Recently, the GPA group generated global, regional and country-specific estimates of the prevalence of psoriasis in children, in adults and in the overall population.[3,4] However, the extent to which the incidence and prevalence of psoriasis vary with age, between genders and over time has not yet been systematically examined. In recent years, a number of studies have been published examining the epidemiology of psoriasis and providing data on temporal trends in the incidence and prevalence of this important skin disease. Such data are important in order to determine whether the global burden of the disease is changing in the context of an ageing population.[5,6] Therefore, the aims of this systemic review were to examine worldwide variations in the prevalence and incidence of psoriasis on the basis of age and gender, and to explore trends in its epidemiology over time.