12% to 30% of inflammatory bowel disease (IBD) cases are diagnosed during childhood.
Extraintestinal manifestations (EIMs), particularly growth delay, may be the predominant presenting feature in childhood IBD.
Coinfection with Clostridium difficile increases morbidity.
Approximately two million people worldwide are afflicted with IBD. IBD is more common in westernized societies and in the northern hemisphere. There is a higher incidence in Caucasians and those of Jewish descent, which may reflect both genetic and environmental contributions. Approximately 12% to 30% of all patients with IBD present during childhood (before 20 years of age).1–3 Pediatric incidence is increasing; currently it is estimated at 0.5 to 34/100,000 for ulcerative colitis (UC) and 0.2 to 58/100,000 for Crohn’s disease (CD).3–8 UC and CD occur equally in the first 8 years of life; CD is more common in older children.9 Most children with IBD present in late childhood/early adolescence, but diagnosis in infancy has been described.1,10,11
The exact pathophysiology of IBD is not well understood. There is likely a combination of environmental, genetic, and immune factors. An environmental trigger may incite a deregulation of immune response to gut flora in a genetically susceptible host.12–15 Patients with IBD have less complex profiles of commensal bacteria and higher numbers of mucosa-associated bacteria as compared to healthy individuals.12 Increased intestinal permeability and food-borne bacterial infections trigger some IBD cases.
Although development of IBD is multifactorial, there are many known risk factors. A family history of IBD carries an 8- to 10-fold greater risk and IBD frequency in first-degree relatives may be as high as 40%.4,16 IBD is particularly severe in Jewish persons with familial Mediterranean fever.17 Pediatric IBD has a stronger genetic correlation, possibly because children have less lifetime exposure to environmental factors.18–20 Infections are also associated with IBD. C. difficile infection can be either an inciting or exacerbating factor.21 An increased risk of IBD has been shown in persons after acute gastroenteritis with Salmonella or Campylobacter.22,23 The risk is highest during the first year after the gastroenteritis episode, but remains high compared to matched controls for up to 15 years.23 Other environmental risk factors include smoking (in CD; smoking is protective against UC), exclusive formula-feeding, a diet high in animal protein and low in fiber,24–27 climate, low vitamin D exposure,28,29 and stress.4 Exercise may be protective against flares.30
Pediatric patients with IBD typically present with signs and symptoms of colitis. Often, they have a subacute illness with abdominal pain and diarrhea (frequently bloody). Fever, fatigue, anemia, and weight loss are also common presenting symptoms in IBD. Symptoms may be persistent (≥4 weeks) or recurrent (≥2 episodes in 6 months).31 EIMs occur in 6% of children upon presentation ...