Objectives: Depending its frequency, the association in the same subject of Crohn's disease and another pathology can be fortuitous or the expression of genetic or environmental interrelationships. The aim of our study was to identify among a series of patients with Crohn's disease preliminary data which would be suggestive of a significant association between Crohn's disease and other pathologies.
Patients and methods: Personal and familial histories were collected in 832 patients with Crohn's disease who were seen consecutively in the same hospital clinic from 1974 to 1994.
Results: We found 4 cases (0.5%) of associated Crohn's disease-multiple sclerosis and Crohn's disease-rheumatoid purpura in the same patient. Each of the following genetic diseases was associated with Crohn's disease in one patient (0.1%): Charcot-Marie-Tooth disease, deuteroanopia, multiple exostosis, familial ichthyosis, periodic disease.
Conclusion: We describe for the first time sporadic cases of associated Crohn's disease and another rare disease, Charcot-Marie-Tooth disease, familial ichthyosis and periodic disease. We suggest that there is a significant interrelationship between personal and familial histories of Crohn's disease and multiple sclerosis which should be verified in prospective studies.