Objectives Imaging studies in patients with cutaneous psoriasis have demonstrated asymptomatic bone and tendon changes, commonly of the foot and ankle. We sought to determine if patients with cutaneous psoriasis have an increased risk of clinically significant foot and ankle tendinopathy or enthesopathy compared with the general population.
Methods Patients with cutaneous psoriasis and a general population cohort were identified in The Health Improvement Network, a general practice medical records database from the UK. All patients with psoriatic arthritis were excluded. Cox proportional-hazards models (α=0.05) estimated the HR for development of foot and ankle tendinopathy or enthesopathy among patients with psoriasis, with adjustment for numerous covariates.
Results In total, 78 630 patients with cutaneous psoriasis and 5 983 338 persons from the general population were identified. In an unadjusted model, patients with cutaneous psoriasis had a 25% increased risk of developing foot and ankle tendinopathy or enthesopathy compared with the general population (HR 1.25, 95% CI 1.20 to 1.30, p<0.0001). The HR remained unchanged and statistically significant after adjusting for covariates, and in sensitivity analyses.
Conclusions These data suggest that patients with psoriasis can have foot and ankle tendinopathy or enthesopathy without having psoriatic arthritis, presenting a diagnostic challenge to physicians. Further research is needed to elucidate mechanisms contributing to this increased risk.
- psoriatic arthritis
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Contributors RTL, IAV and CB developed the study topic. LMP, JML and CB contributed expert advice on psoriasis, psoriatic arthritis and tendinopathy/enthesopathy. RTL, LMP, JML and CB reviewed Read codes corresponding to the present study. IAV, ADF and MWL contributed to data systems development and extraction. GGK, SBP and CB provided methodological expertise. Statistical analyses were performed by IAV with critical review by RTL, GGK, SBP and CB. RTL drafted the manuscript, tables and figures, with all authors providing critical review. All authors approved the final version of this manuscript.
Funding This study was funded by a studentship from the Canadian Association of Psoriasis Patients and the Canadian Institutes of Health Research.
Competing interests None declared.
Patient consent Not required.
Ethics approval Approved by the University of Calgary Conjoint Health Research Ethics Board and the UK IMS Health Scientific Review Committee.
Provenance and peer review Not commissioned; externally peer reviewed.
Correction notice This article has been corrected since it first published. Figures 1 and 2 have been transposed so that they are with the correct figure legend.
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