Psoriasis comorbidities: results from the National Psoriasis Foundation surveys 2003 to 2011

Background: Studies examining comorbidities among psoriasis patients with varying disease severities measured by body surface area (BSA) are lacking.

Objective: To examine the association between psoriasis severity and comorbid conditions, including rheumatologic, cardiovascular and other immune-mediated diseases.

Methods: From 2003 to 2011, the National Psoriasis Foundation conducted surveys among 5,604 psoriasis patients. The combined surveys represented the largest study to date that used BSA as a direct measure of psoriasis severity for comorbidity assessment.

Results: Over 86% of psoriatic arthritis (PsA) patients reported presenting with psoriasis prior to PsA; the diagnosis of psoriasis preceded that of PsA by a mean period of 14.6 years. Compared to those with mild psoriasis, patients with moderate-to-severe psoriasis had significantly increased adjusted odds of PsA (moderate: odds ratio, OR: 1.21, 95% confidence interval, CI: 1.04-1.41; severe: OR: 2.32, 95% CI: 1.98-2.70). Patients with severe psoriasis had increased adjusted odds of diabetes (OR: 1.5, 95% CI: 1.08-2.08) and cardiovascular disease (OR: 1.5, 95% CI: 1.01-2.24) compared to those with mild-to-moderate psoriasis. Odds of rheumatoid arthritis, ankylosing spondylitis, lupus, Crohn's disease and multiple sclerosis were not significantly increased in patients with severe psoriasis.

Conclusion: Compared to those with mild-to-moderate psoriasis, patients with severe psoriasis are at increased odds of PsA, diabetes and cardiovascular diseases.