Microscopic Colitis and Risk of Incident Psoriasis: A Nationwide Population-Based Matched Cohort Study

Abstract

Background

Microscopic colitis (MC) has been associated with several immune-mediated diseases including psoriasis, but earlier research has been limited to psoriasis occurring before MC. Data from large-scale cohort studies investigating MC and risk of future psoriasis are lacking.

Objective

To examine the association between MC and psoriasis.

Methods

In a nationwide, population-based, matched cohort study in Sweden from 2007 to 2021, we identified 8404 patients with biopsy-verified MC (diagnosed in 2007–2017), 37,033 matched reference individuals, and 8381 siblings without MC. Information on MC was obtained through the ESPRESSO cohort (a Swedish histopathology database with nationwide coverage). Using Cox regression, we calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for psoriasis up until 2021.

Results

During a median follow-up of 9.2 years (interquartile range = 6.7–11.7), 179 MC patients and 440 reference individuals were diagnosed with psoriasis (241.1 vs 131.8 events per 100,000 person-years), corresponding to one extra case of psoriasis in 91 patients with MC over 10 years. After adjustment for the matching variables (birth year, sex, county of residence, and calendar period) and level of education, we computed an adjusted hazard ratio (aHR) of 1.82 (95% CI = 1.53–2.17). Stratified by sex, estimates were similar and when examining the aHR across different lengths of follow-up, we found significantly elevated estimates up to 10 years after MC diagnosis. Compared to MC-free siblings, the aHR was 1.85 (95% CI = 1.36–2.51).

Conclusion

Patients with MC are at an almost doubled risk of psoriasis compared to the general population. Clinicians need to consider psoriasis in MC patients with skin lesions.

Keywords:

• microscopic colitis
• psoriasis
• epidemiology

Abbreviations

aHRs, adjusted hazard ratios; ATC, anatomical therapeutic chemical; BMI, body mass index; COPD, chronic obstructive pulmonary disease; CC, collagenous colitis; CI, confidence interval; ESPRESSO, Epidemiology Strengthened by histoPathology Reports in Sweden; GI, Gastrointestinal; IBD, Inflammatory bowel disease; ICD, International Classification of Diseases and Related Health Problems; IQR, interquartile range; IR, incidence rate; LC, lymphocytic colitis; MC, microscopic colitis; NPR, National Patient Register; OR, odds ratio; PPV, positive predictive value; SNOMED, Systematized Nomenclature of Medicine.

Details of Ethics Approval

This study was approved by the Regional Ethics Committee, Stockholm, Sweden (Protocol no 2014/1287-31/4, 2018/972-32 and 2022-05774-02).

Data Transparency Statement

In accordance with Swedish regulations, the data from this study are not publicly available.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Dr. Ludvigsson has coordinated a study on behalf of the Swedish IBD quality register (SWIBREG). That study received funding from the Janssen corporation. Dr Ludvigsson has also received financial support from MSD to develop a paper reviewing national healthcare registers in China. Dr. Ebrahimi has served as an advisory board member for Boehringer Ingelheim. Dr Svedbom has received consultancy fees from ICON plc, AbbVie, BMS, Novartis, and Eli Lilly. Dr Svedbom has received lecture fees from Janssen Cilag and UCB. Dr Ståhle has received lecture fees and consulted for Leo Pharma, AbbVie, Eli-Lilly, Lipidor, UCB Pharma, Bristol-Myers Squibb and Janssen. Dr Ståhle serves as scientific chairman in Swedish Dermatology Foundation (Hudfonden) receiving honoraria. The authors report no other conflicts of interest in this work.

Additional information

Funding

This work was supported by the Karolinska Institutet (Ludvigsson), Stockholm County Council (Ludvigsson), the NIH (National Institutes of Health NIA R01 (AG068390; Ludvigsson)). None of the funding organizations has had any role in the design and conduct of the study, in the collection, management, and analysis of the data, or in the preparation, review, and approval of the manuscript.