Chronic Inflammatory Bowel Disease in Childhood
Molly O'Gorman MD1
Alan M. Lake MD2
1 Senior Fellow in Pediatric Gastroenterology
2 Associate Professor of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD.
Definition
Chronic inflammatory bowel disease (IBD) of childhood is generally defined as either ulcerative colitis (UC) or Crohn disease (CD). The inflammation of UC is restricted to the mucosal lining of the colon, with the colonic involvement beginning universally in the rectum and extending proximally continuously. Although proctitis, persistent isolated involvement of the rectum, is common in adults (40%), it is rare in children (<10%). In contrast, the enteric inflammation of CD is transmural and involves any level of the intestinal tract discontinuously. The intervals of relatively normal bowel are termed "skip areas." In CD, characteristic lesions range from oral ulcerations to perianal lesions, although the most frequently involved area is the terminal ileum of the small bowel, a process termed ileitis.
Recognition of these conditions by pediatricians is important because the peak incidence of IBD is in the second decade. Fewer than 5% of patients are diagnosed prior to age 5 years. In many children presenting with isolated colitis, the diagnosis of the chronic inflammation of IBD is established by biopsy before a clinical distinction between UC and CD can be established. These children carry the diagnosis of chronic nonspecific colitis or colitis type indeterminant. In our experience, the disease in approximately 50% of these children evolves within 5 years into more classic cases of UC or CD.
