[The clinical activity of Crohn's disease in the Paris area is maximal in the spring].

The aim of this study was to look for seasonal fluctuations in the clinical course of Crohn's disease. Eighty-three patients residing in the Paris area were included in the study and they had all undergone continuous clinical monitoring throughout the first three years of the disease. During this period, the clinical activity of the disease was ranked monthly on a semi-qualitative scale ranging from 0 to 4. The dates of corticosteroid treatment and of resection surgery carried out during the first three years of the disease were also recorded. The mean clinical score varied significantly (P < 0.0001) for different months of the year, the three highest scores being recorded during the three months of Spring-time (April, May and June). The number of months of corticosteroid treatment differed significantly (P < 0.05) for the various seasons, the six highest values being reported during Spring and Summer months. The number of intestinal resections differed significantly (p < 0.05) during different seasons, the highest incidence again being reported during Spring. This study demonstrates seasonal variations in the clinical course of Crohn' disease in the Paris area, with a peak occurring in the Spring.