Crohn disease (CD), or Crohn’s disease, is a chronic inflammatory bowel disease. Once considered rare in the pediatric population, Crohn disease is recognized with increasing frequency among children of all ages. Approximately 20-30% of all patients with Crohn disease present when they are younger than 20 years.
The pathogenesis of Crohn disease is multifactorial. After a triggering event occurs in a genetically susceptible individual, an altered immune response leads to chronic inflammation of the intestine. Although the etiology of the precipitating event is unknown, luminal bacteria or specific antigens are thought to be involved.
The macroscopic findings at the time of endoscopy and colonoscopy or surgery include various degrees of edema, erythema, ulceration, friability, thickening of the bowel wall and mesentery, and extension of fat over the serosal surface of the intestine.
Skipped areas of inflammation anywhere in the upper or lower GI tract are characteristic of Crohn disease, in contrast to the continuous diffuse colonic inflammation found with ulcerative colitis(UC). Microscopic findings on intestinal mucosal biopsy consist of chronic inflammation with architectural distortion. Granulomas are sometimes noted on biopsy findings in Crohn disease.
Patients with suspected Crohn disease (CD), or Crohn’s disease, should initially be evaluated by their primary care team. The patients’ symptoms should be elicited in detail. A medical history, detailed review of systems, and family history should be obtained, and growth parameters should be documented.
A careful assessment of growth and development is an important part of evaluating the pediatric patient. Growth abnormalities may be detected by evaluating several parameters: height and weight, percentage height and weight for the patient’s age and percentage weight for the patient’s height, growth velocity, body composition on anthropometry, and skeletal bone age.
Vital signs are usually normal, although tachycardia may be present with anemic patients. Chronic intermittent fever is a common presenting sign.
Body weight and height may reveal weight loss and growth delay.
Abdominal findings may vary from normal to those of an acute abdomen. Diffuse abdominal tenderness is often present. Fullness or a discrete mass may be appreciated, typically in the right lower quadrant of the abdomen, which may represent a palpable thickened loop of bowel.
Perianal disease (eg, skin tags, abscesses, fistulae, fissures) is present in approximately 45% of patients.
Pubertal delay may precede the onset of intestinal symptoms, and accurate Tanner staging should be a part of routine physical examination.