Background  Psoriasis is a chronic debilitating disease affecting approximately one million Canadians. The objective of this study is to estimate the economic burden in $CDN (2008) of moderate to severe plaque psoriasis among Canadian adults.

Methods  Using a cross-sectional design, direct resource use, costs, lost productivity, and quality of life were obtained for 90 subjects diagnosed with psoriasis in three dermatology clinics in British Columbia, Ontario, and Québec. An Excel-based economic model was developed to project the annual cost of psoriasis, from the societal perspective.

Results  The estimated mean annual cost of psoriasis was $7999/subject (95% CI: $3563–$12,434) with direct costs accounting for 57%. Mean lost productivity costs, which accounted for 43% of the mean annual costs of psoriasis, were $3442/subject (95% CI: $1293–$5590).

Conclusion  Projecting the mean costs per patient to the afflicted population yields an estimated total annual cost of $1.7 billion (95% CI: $0.8–$2.6 billion) attributable to moderate to severe psoriasis in Canada. Understanding the interplay between direct costs, lost productivity, and quality of life is critical for accurately identifying and evaluating effective treatments for this disease.