Psoriasis prevalence among adults in the United States.

Background: Psoriasis is a chronic inflammatory disorder associated with significant morbidity and mortality. Up-to-date prevalence data on psoriasis provide the foundation for informing population research, education, and health policy.

Objective: We sought to determine the prevalence of psoriasis among US adults.

Methods: We performed a cross-sectional study using National Health and Nutrition Examination Survey 2009 through 2010 data to determine psoriasis prevalence rates.

Results: From 6218 participants older than 20 years of age, 6216 respondents provided complete information regarding a psoriasis diagnosis. The prevalence of psoriasis among US adults ages 20 years and older is 3.2% (95% confidence interval [CI] 2.6%-3.7%). A total of 7.2 million US adults had psoriasis in 2010; an estimated 7.4 million US adults were affected in 2013. When stratifying the sample by race among those between ages 20 and 59 years, the psoriasis prevalence was highest in Caucasians at 3.6% (95% CI 2.7%-4.4%), followed by African Americans (1.9%; 95% CI 1.0%-2.8%), Hispanics (1.6%; 95% CI 0.5%-2.8%), and others (1.4%; 95% CI 0.3%-2.6%). The prevalence of psoriasis among US adults has not changed significantly since 2003 to 2004 (P > .05).

Limitations: Dermatologist evaluation and skin photographs were unavailable for the 2009 through 2010 surveys.

Conclusions: In the United States, psoriasis remains a common, immune-mediated disease, affecting 7.4 million adults. Its prevalence has remained stable since the mid-2000s.