Seasonal Pattern in the Relapses of Crohn's Disease and Ulcerative Colitis in British Columbia

Abstract

Ulcerative colitis (UC) reportedly has a seasonal variation of exacerbations. No seasonal variation of relapses in Crohn's disease (CD) has been reported. A retrospective study of the monthly distribution in the relapses of inflammatory bowel disease (IBD) demonstrated seasonality in both UC and CD. From 1971-93, 226 patients (CD=139, UC=87) with regular follow-ups for at least 13 consecutive months were analyzed. In the study period, 592 relapses occurred in CD patients and 300 in UC patients. The peak relapse seasons were autumn and winter and the lowest was summer, for both CD and UC. The seasonal pattern was independent of sex. These results support the view that seasonal factors may be involved in the relapse of IBD.

Effects of temperature, weather, seasons, atmosphere, and climate on the exacerbation of inflammatory bowel diseases: A systematic review and meta-analysis

“…When examining the studies that were not included in the meta-analysis, it seems that IBD exacerbation tended to occur slightly more frequently in warmer seasons. First, among the ten studies that reported a significant correlation between seasonal variation and IBD exacerbation, six reported a significant correlation with spring or summer [ 22 , 25 , 26 , 46 , 48 , 50 ], and the remaining three reported a correlation with winter or autumn [ 18 , 19 , 49 ]; in one study, both spring and autumn were reported ( Table 1 ) [ 20 ]. Second, two studies that reported the relationship between short-term extreme temperature change and IBD exacerbation support our hypothesis that warmer seasons were associated with more IBD exacerbations.…”

“…Furthermore, only 6 out of 20 studies reported information on the duration of IBD morbidity, location of lesions, or medications administered [ 20 – 24 , 50 ]. Moreover, 7 out of 20 studies did not report the number of patients who experienced IBD exacerbations [ 18 , 20 , 26 , 27 , 49 , 51 , 52 ], and 6 of the 11 studies reported different numbers of patients and cases of exacerbations [ 19 , 21 , 22 , 25 , 48 , 50 ]. The abovementioned factors might have resulted in the underestimation or overestimation of the pooled estimate results of the meta-analysis.…”

“…Our study included a total of 20 studies on the effects of temperature, weather, season, and atmosphere on the exacerbation of IBD [18][19][20][21][22][23][24][25][26][27][45][46][47][48][49][50][51][52][53][54], and a meta-analysis of the correlation…”

“…In contrast, a largescale cohort study in Sweden showed a significant correlation of the onset of IBD symptoms with the season or month of birth [15,16]. Thereafter, some case-series showed that exacerbation was significantly related to a specific month in pediatric or adult UC patients [17], although subsequent studies on IBD exacerbation provided conflicting results [18][19][20][21][22][23][24][25][26][27].…”