Anal lesions: any significant prognosis in Crohn's disease?

Work-up of anoperineal lesions usually includes indices of clinical activity as well as diagnostic criteria of Crohn's disease but their prognostic implication remains unclear. This prospective study was conducted in order to evaluate the overall incidence of anoperineal lesions and their relation to the natural history of underlying intestinal Crohn's disease with special reference to the steroid-dependent state of the patients.

One hundred and one patients (46 males, 55 females, aged 34 +/- 14 years; range: 15-79) were consecutively referred to our institution (May 1991 to May 1994) for intestinal symptoms related to Crohn's disease (mean duration 66 +/- 66 months). They all underwent a proctological examination regardless of perineal symptoms. The Cardiff classification was used to describe anoperineal lesions. Patients with anal lesions (64) differed from those without (37): male predisposition (53% vs. 32%, P<0.05), more frequent rectal involvement (75% vs. 24%, P<0.001) and more acute lesions observed at proctoscopic examination (42% vs. 16%, P<0.05). Age of onset, surgical past history of Crohn's disease, colonic or ileal involvement, or Harvey-Bradshaw score were not different between groups.

Patients with anal ulceration (43) as compared to patients having anal involvement without ulceration experienced pain more frequently (constant pain: 56 vs. 14%; defecatory pain: 35 vs. 19%) and a more severe evolution of intestinal (40 vs. 22%, P<0.05) and anal (42 vs. 12%, P<0.05) involvement. In those with an aggressive ulceration (U2, 28 patients), daily stool frequency (5.1 +/- 3 vs. 3.6 +/- 2.5, P<0.05) and clinical score (9 +/- 5 vs. 7 +/- 3) were more pronounced. Steroid therapy dependency occurred more frequently in the group with anal ulceration (35 vs. 16% and 40 vs. 17%, respectively, P<0.05). Similar associations were observed for cases of anal involvement (34 vs. 5%, P<0.01) and azathioprine was more frequently required (39 vs. 5%, P<0.01) than in those free of anal lesions. During follow-up, eight other patients required azathioprine (steroid dependence in six) and seven of them had anal lesions at referral. At the endpoint of the study, one out of two patients with anal lesions required azathioprine most often due to steroid dependency of the intestinal involvement (30/64 vs. 4/37, P<0.005).

Anal ulcerations are a reliable severity index of Crohn's disease in both short- and long-term prognosis but their link to the steroid status of the intestinal disease remains unclear.