Psoriasis, psoriatic arthritis (PsA), and inflammatory bowel disease (IBD) are related inflammatory immune-mediated diseases, with considerable overlap. However, it is as yet unclear whether co-occurrence of these diseases affects disease course and characteristics of the individual complaints. The objective of this study was to identify the prevalence of IBD and PsA in a psoriasis cohort and to examine whether patients with concurrent psoriasis and IBD carry a distinct phenotype.
Data of all patients with psoriasis visiting a general hospital in the Netherlands between 2009 and 2014 were retrospectively retrieved from electronic patient files. In addition, clinical characteristics of patients with concurrent psoriasis and IBD (n = 40) were compared with psoriasis-only (n = 1643) and IBD-only (n = 385) cohorts.
Among 1669 hospital-based patients with psoriasis, prevalence of PsA was 12.2% (n = 203, 95% confidence interval, 10.5–13.7) and of IBD 1.6% (n = 26, 95% confidence interval, 1.0–2.2), including 12 Crohn's disease (CD) and 14 ulcerative colitis. Psoriasis-PsA patients were more likely to have IBD than psoriasis-only patients (3.0 versus 1.4%).
Psoriasis-CD patients were younger at CD diagnosis (20.0 versus 32.0 yr, P = 0.001), and psoriasis diagnosis (28.0 versus 43.5 yr, P = 0.004) than psoriasis-only patients. Psoriasis-IBD patients had a mild psoriasis phenotype similar to psoriasis-only patients, but the CD-phenotype was significantly more severe than in CD-only patients.
The prevalence of IBD in psoriasis was approximately 4 times higher than that in the general population, with the highest risk for psoriasis-PsA patients. Psoriasis-CD patients have a mild (early-onset) psoriasis but an earlier-onset and severe CD-phenotype.
Supplemental Digital Content is Available in the Text.Article first published online 14 June 2017.
Departments of *Dermatology and
†Gastroenterology and Hepatology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, the Netherlands; and
‡Department of Dermatology, Medical Centre Leeuwarden (MCL), Leeuwarden, the Netherlands.
Address correspondence to: Hester Eppinga, MD, PhD, Burgemeester s' Jacobplein 51, 3015 CA Rotterdam, the Netherlands (e-mail: firstname.lastname@example.org).
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.ibdjournal.org).
The authors have no conflict of interest to disclose.
Received January 04, 2017
Accepted April 24, 2017