The prevalence of previously diagnosed and undiagnosed psoriasis in US adults: Results from NHANES 2003-2004
Accepted 17 September 2008. published online 21 November 2008.
Background
Psoriasis is a predictor of morbidity. It is important to determine the extent to which psoriasis remains undiagnosed.
Objective
To determine the prevalence of psoriasis.
Methods
We conducted a cross-sectional study using the National Health and Nutrition Examination Survey 2003-2004.
Results
The prevalence of diagnosed psoriasis was 3.15% (95% confidence interval [CI], 2.18-4.53), corresponding to 5 million adults. Approximately 17% of these patients have moderate to severe psoriasis based on body surface area report and 25% rate psoriasis a large problem in everyday life. The prevalence of undiagnosed active psoriasis by conservative estimate was 0.4% (95% CI, 0.19-0.82), corresponding to approximately 600,000 US adults, and 2.28% (95% CI, 1.47-3.50) by a broader definition, corresponding to 3.6 million US adults. Undiagnosed patients had a trend toward being more likely to be male, nonwhite, less educated, and unmarried compared with patients who had received a diagnosis.
Limitations
The method for determining the presence of psoriasis had limited ability to detect mild disease and only fair interrater agreement.
Conclusion
More than 5 million adults have been diagnosed with psoriasis. A large number have undiagnosed psoriasis and there are important disparities which may be associated with not receiving medical attention.
aDepartment of Dermatology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
bCenter for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
Correspondence to: Joel M. Gelfand, MD, MSCE, University of Pennsylvania, Department of Dermatology, 3600 Spruce St, 2 Maloney Building Suite 2M47, Philadelphia, PA 19104.
Supported in part by a National Research Service Award from the National Institute of Health (to S.K.K.) and a grant K23AR051125 from the National Institutes of Health/National Institute of Arthritis, Musculoskeletal, and Skin Diseases (to J.M.G.).
ABSTRACT