Background: Ulcerative proctitis (UP) is limited in the rectum. Therefore, local mesalamine is a mainstay of maintenance therapy. In some UP patients, skip inflammation such as patchy or segmental inflammation is noted in the right-sided colon. However, its clinical significance is currently unclear. Considering the local action of mesalamine suppository or enema, the clinical efficacy of additional oral mesalamine therapy remains questionable. The aim of this study was to evaluate the clinical features and course of UP with skip inflammation according to the additional use of oral mesalamine.
Methods: Data of 388 patients (median age 39 years) with an initial diagnosis of UP at Daehang Hospital, Seoul from January 2005 to October 2016 were reviewed. Each UP patient with skip inflammation was matched with controls (UP patients without skip inflammation) at 1:2. To reduce biases, controls were matched with cases for age, gender, and initial disease activity. Study outcomes were extent progression and acute exacerbation (condition requiring corticosteroid). Patient demographics, endoscopic findings, clinical course, and medication history were also analyzed.
Results: During the follow-up period (median, 69.5 months; range, 12–153 months), the overall extent progression rates of the control group (n=192) versus the skip-inflammation group (n=96) were 13.5% vs. 9.9% at 5 years and 24.0% vs. 32.9% at 10 years (log rank p=0.71). In the skip-inflammation group, the extent progression rates at 5 and 10 years were not significantly different either between the combination mesalamine group and the local mesalamine group (7.2% vs. 14.6% for 5 years and 33.4% vs. 26.6% for 10 years, log rank p=0.96).
The overall exacerbation rates of the control group versus the skip-inflammaiton group were 13.0% vs. 10.2% at 5 years and 17.2% vs. 26.8% at 10 years (log rank p=0.68). In the skip-inflammation group, the exacerbation rates were not significantly different between the combination mesalamine group and the local mesalamine group either (12.8% vs. 6.1% at 5 years and 26.6% vs. 23.6% at 10 years, log rank p=0.88).
Conclusions: In UP patients with skip inflammation, combination mesalmine maintenance therapy tends to be preferred over single local mesalamine therapy. However, additional oral mesalamine does not significantly affect the clinical course of ulcerative proctitis with skip inflammation.