Risk of uveitis and inflammatory bowel disease in people with psoriatic arthritis: a population based cohort study

Background: The risk of uveitis in patients with psoriatic arthritis (PsA) is well documented however, the magnitude of risk of uveitis and inflammatory bowel disease (IBD) in people with PsA or psoriasis is less consistent in the literature. The aim of this study was to calculate the incidence and prevalence of uveitis and IBD in patients with PsA and psoriasis alone and compare this with the general population in the UK.

Methods: Incident cases of PsA, aged 18–89 at time of diagnosis, were identified from the Clinical Practice Research Datalink, 1998–2014 using Read codes and prescription data. Cases of PsA were matched by age, sex, general practice, and the date of the PsA diagnosis (index date) to two randomly selected cohorts: patients with psoriasis only and a general population cohort with no PsA or psoriasis. Prevalent cases of uveitis and IBD had an earliest date of diagnosis on or before their index date; incident cases were those with a first date of diagnosis after their index date. Incidence Rate Ratios of uveitis and IBD in psoriatic disease compared with the general population were calculated using Poisson regression.

Results: There were 6,783 (49% males) incident cases of PsA that were matched to 27,132 patients with psoriasis and 27,132 patients from the general population. The mean age at PsA diagnosis was 49.2 years. The prevalence on the index date, and incidence rates of uveitis and IBD in the study population are shown in Table 1. The incidence of uveitis was significantly higher in patients with PsA and with psoriasis than in the general population. The incidence of Crohn’s Disease, but not Ulcerative Colitis (UC) was higher in patients with PsA than in the general population but not in patients with psoriasis alone.

Conclusion: In this large population based study we report an increased risk of developing Crohn’s Disease, but not UC, among patients with PsA. We also report an increased risk of developing uveitis among patients with PsA over those with psoriasis alone or the general population.