Microscopic colitis in Uppsala health region, a population-based prospective study 2005–2009

Abstract

Objective. The aim of this study is to report on the incidence of microscopic colitis (MC), any possible relation with inflammatory bowel disease (IBD), concomitant drug consumption, related diseases and the clinical course of the diseases. Methods. Both new cases of IBD and MC were registered at the same time in the same geographical area. The study started in the county of Uppsala 2005–2006, and other parts of the surrounding health region were included 2007–2009. Established morphological criteria were used, i.e. a layer of subepithelial collagen band ≥ 10 μm in collagenous colitis (CC) with concomitant inflammation and at least 20 lymphocytes per 100 epithelial cells in lymphocytic colitis (LC). Results. The authors found 272 new cases of MC, 154 with CC and 118 with LC. The mean age-adjusted incidence was 7.0/1,000,000 for CC and 4.8/100,000 for LC. The clinical course was dominated by single episodes with diarrhea or intermittent symptoms, but 14% suffered from chronic diarrhea. In 10% of the cases, diagnosis was made in individuals without chronic watery diarrhea. Although not systematically tested, concomitant celiac disease was found in approximately 5% of the patients. Conclusions. The incidence of MC in Uppsala health region is similar to other studied areas. The majority of patients had a self-limiting or easily treated condition, but 14% need a more or less continuous medication. Ten percent of the patients demonstrate other symptoms than chronic watery diarrhea. The possibility of concomitant celiac disease should be considered in new cases of MC.

Key Words::

• colitis
• collagenous
• epidemiology
• lymphocytic

Acknowledgements

The study was supported by grants from the Uppsala University Hospital Research Foundation and the Uppsala-Örebro Regional Research Council. The sponsors had no involvement in study. The authors had no writing assistance. A Rönnblom collected data, performed the statistical analyses and drafted the manuscript. D Sjöberg collected data and performed the age adjustment and Poisson distribution. T Holmström, M Larsson, AL Nielsen and L Holmquist collected data. A Ekbom gave significant advice regarding the environmental factors. A Wanders and U Thelander examined the histological preparations. M Thörn collected data and was the co-writer of the manuscript. All authors participated in the design of the study, read and approved the final manuscript.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.