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A 12-year-old female presents with cramping abdominal pain, a ten pound weight loss, diarrhea, and bloody stools. Physical examination is remarkable for oral aphthous ulcers, mild right lower quadrant tenderness, and perianal skin tag at six o'clock position. Further laboratory work up reveals anemia (hemoglobin 7.2 g/dL) and elevated erythrocyte sedimentation rate (41 mm/hr). She was referred to pediatric gastroenterology and underwent an esophagogastroduodenoscopy and colonoscopy, which was visually and histologically remarkable for gastritis, duodenitis, pan-colitis, and terminal ileitis (Figure 59-1 and 59-2). She was diagnosed with Crohn disease.
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Inflammatory bowel disease (IBD) refers to two chronic conditions of the gastrointestinal tract: Crohn disease (CD) and ulcerative colitis (UC), that frequently have their presentations in the late childhood and adolescence. IBD is one of the most common chronic diseases of childhood and adolescents.
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Crohn's Disease, Ulcerative Colitis (UC), Indeterminate Colitis.
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Pediatric-onset inflammatory bowel disease (IBD) has been significantly increasing in prevalence and incidence worldwide over the past few decades.1
It is currently estimated that as many as 1.4 million persons in the US and 2.2 million persons in Europe suffer from these diseases.2 More than 20 percent of patients present during childhood and diagnosed before the age of 10 years and fewer than 5 percent diagnosed before age 5 years.3
The mean age at diagnosis of pediatric IBD in the US is 12.5 years.3
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Etiology and Pathophysiology
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IBD is characterized by chronic inflammation of the gastrointestinal tract and encompasses two entities: CD and UC.
The pathogenesis of IBD remains elusive, but involves an interaction between a genetic predisposition, defects of host immunoregulation, environmental factors, and an imbalance in the intestinal microbiota (dysbiosis). Dysbiosis (also called dysbacteriosis) is considered crucial for the development of chronic intestinal inflammation.
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Up to 25 percent of children who develop IBD have a positive family history of IBD. Children who have a first-degree relative affected by either UC or CD have a 10 to 13 times higher risk for developing IBD.4
Monozygotic twin concordance is approximately 50 percent for CD and nearly 20 percent for UC.5
Genetic linkage analyses and genome-wide association studies have identified numerous IBD candidate genes. NOD2/CARD15 gene, located on chromosome 16q has been associated with CD.
Anti-Saccharomyces cerevisiae antibody (ASCA) is found in 50 to 60 percent of patients who have CD.
Perinuclear antineutrophil antibody (pANCA) is detected in approximately 70 percent ...