Supplementary Material for: Prevalence of Skin and Skin-Related Diseases in the Rochester Epidemiology Project and a Comparison with Other Published Prevalence Studies

In Olmsted County, Minn., USA, reliable, population-based epidemiologic research studies can be performed because of a unique medical records linkage system, the Rochester Epidemiology Project (REP). Our objective was to summarize the epidemiologic data describing the prevalence of skin and skin-related diseases derived from the REP and to compare the findings with those from other studies worldwide. Retrospectively, we reviewed the results of population-based REP studies reporting the prevalence of skin and skin-related diseases over more than 4 decades and compared them to other published prevalences globally. Prevalences from the REP reported per 100,000 persons were as follows: hidradenitis suppurativa, 130.0; psoriasis, 700.0; psoriatic arthritis in 1992, 100.0, and in 2000, 160.0; Behçet disease, 5.2; scleroderma, 13.8; dermatomyositis, 21.42; systemic lupus erythematosus (SLE), from 30.5 to 122.0 suspected SLE, 32.8; combined SLE, 41.8; discoid lupus erythematosus, 27.6, and cutaneous lupus erythematosus, 70.4 and 73.2 (from 2 studies). Many of the population-based prevalences of specific skin and skin-related diseases derived from the REP are different from those estimated globally. Suggested reasons for disparity in the prevalences globally may include differences in the type of reported prevalence, study methodology, geographic areas, ethnic groups, age distribution, and socioeconomic status.