Associated comorbidities in psoriasis and inflammatory bowel disease

Background The association between psoriasis and inflammatory bowel disease (IBD) has been previously reported although a great deal remains unknown about associated comorbidities. Objectives The aim of this study was to examine comorbidities in individuals diagnosed with both psoriasis and IBD, and to compare those with individuals diagnosed with psoriasis‐only. We also looked at differences within the IBD group by clearly defining that cohort. Methods We included 146 patients diagnosed with both psoriasis and IBD and 146 controls diagnosed of psoriasis‐only without previous records of IBD, matched by gender, ethnicity and age (±5 years). Patients were obtained from the research patient data repository of Brigham and Women’s Hospital (BWH) and Massachusetts General Hospital. Controls were obtained from the psoriatic arthritis and psoriasis follow‐up study (PAFS) at BWH. The comparison between the two groups included socio‐demographics, comorbidities and laboratory inflammation parameters. Results Compared to individuals with psoriasis‐only, patients with both psoriasis and IBD had significantly higher rates of autoimmune thyroiditis (2.1% vs. 6.8%), hepatitis (0.7 vs. 6.2%) and diabetes (11.0% vs. 26.7%). In addition, of the 146 patients with psoriasis and IBD, 60 (41.1%) were diagnosed with seronegative arthritis. The average C‐reactive protein (CRP) and erythrocyte sedimentation rate (ESR) of the last visits in our clinics were significantly elevated compared to the individuals with psoriasis‐only (ESR, 33.5 vs. 4.0 mm/h; CRP, 9.1 vs. 2.3 mg/L; both P‐values