Natural history of perianal fistulizing lesions in patients with elderly-onset Crohn’s disease: a population-based study

INTRODUCTION: Most studies of elderly-onset Crohn's disease (CD, diagnosed in patients aged 60 or over) have described a mild course. However, data on the natural history of perianal fistulizing CD (pfCD) in this population are scarce. In a population-based cohort study, we described the prevalence, natural history and treatment of pfCD in patients with elderly-onset CD vs. patients with pediatric-onset CD. PATIENTS AND METHODS: All patients diagnosed with CD at or after the age of 60 between 1988 and 2006 were included (n=372). Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD. RESULTS: Thirty-four elderly patients (9%) had pfCD at diagnosis. After a median follow-up of 6 years [IQR: 3-10], 59 patients (16%) had pfCD; the same prevalence (16%) was observed in pediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD (22% vs. 4%, respectively; p<10-4). Rectal CD at diagnosis was associated with pfCD (hazard ratio [95% CI]=2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% (14 out of 59) had a definitive stoma at last follow-up. CONCLUSION: During the first 6 years of disease, the prevalence of pfCD was similar in elderly and pediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.