Presentation and disease course in early- compared to later-onset pediatric Crohn's disease.

Background: The relationship between the age at diagnosis and disease course is poorly defined in children with Crohn's disease (CD). We examined the presentation and course of disease in patients 0-5 compared to 6-17 yr of age at diagnosis.

Methods: We analyzed uniform data from 989 consecutive CD patients collected between January 2000 and November 2003, and stored in the Pediatric IBD Consortium Registry. The statistical tests account for the length of follow-up of each patient.

Results: In total, 98 patients (9.9%) were of 0-5 yr of age at diagnosis. The mean follow-up time was 5.6 +/- 5.0 yr in the younger group and 3.3 +/- 2.8 yr in the older group (P < 0.001). Race/ethnicity differed by the age group (P= 0.015); a larger proportion of the younger group was Asian/Pacific Islander or Hispanic, and a larger proportion of the older group was African American. The initial classification as ulcerative colitis or indeterminate colitis was more common among the 0-5 yr of age group (P < 0.001). The 6-17 yr of age patients presented with more abdominal pain (P < 0.001), weight loss (P= 0.001), or fever (P= 0.07), while the 0-5 yr of age patients presented with more rectal bleeding (P= 0.008). The 6-17 yr of age patients were more likely to be treated with antibiotics (P < 0.001), 6-mercaptopurine/azathioprine (P < 0.001), infliximab (P= 0.001), or corticosteroids (P= 0.0006). The 6-17 yr of age patients had a higher cumulative incidence of treatment with 5-aminosalicylates (P= 0.009) or methotrexate (P= 0.04). The risk for developing an abscess (P= 0.001), a fistula (P= 0.02), a stricture (P= 0.05), or a perianal fissure (P= 0.06) was greater in the 6-17 yr of age patients.

Conclusions: The 6-17 yr of age patients with CD appear to have a more complicated disease course compared to 0-5 yr of age children. The 0-5 yr of age group may represent a unique disease phenotype and benefit from different approaches to management. Long-term prospective studies are required to validate these findings.