ReviewCrohn Disease: Epidemiology, Diagnosis, and Management
Section snippets
Epidemiology
The prevalence of CD has an incidence of 3 to 20 cases per 100,000.4 Crohn disease is more common in the industrialized world, particularly in North America and Western Europe, though the incidence is rising in Asia and South America.7, 8 There may be a slightly higher predominance of CD in women and it is more common in individuals of Ashkenazi Jewish origin than in non-Jews. The exact pathogenesis of CD is unknown, although there are a number of genetic and environmental factors that have
Risk Factors
Risk factors for the development of CD appear to be related to changes in the gut microbiome or disruptions to the intestinal mucosa and genetics.
Location of Disease, Disease Subtype, and Severity of Disease
Crohn disease is characterized on the basis of disease location and phenotype.
Differential Diagnosis
Many conditions can mimic CD. All patients with diarrhea should be assessed for infection, IBD, and in certain cases celiac disease as well. Other conditions that may present similar to CD include appendicitis, Behcet disease, and UC. It is important to rule out infection and other causes of gastrointestinal symptoms even when patients with known CD are having “flares.”
Diagnosis
The diagnosis of CD is a clinical one and can be quite difficult given that the presenting symptoms can be insidious and nonspecific.5 Red flag symptoms that require further evaluation include weight loss, bloody diarrhea, iron deficiency, and night-time awakenings. Similarly, significant family history of IBD, unexplained elevations in the c-reactive protein level, sedimentation rates, or other acute-phase reactants (eg, ferritin and platelets), or low B12 should prompt further investigation
Treatment
The treatment of CD depends on disease severity, location of disease, and subtype of disease (ie, inflammatory, stricturing, or penetrating). We now also attempt to determine who is at risk for aggressive CD and who may require earlier and more aggressive therapies. Risk factors for aggressive disease activity include age of diagnosis less than 30 years, extensive anatomic involvement, perianal disease, deep ulcers, prior surgery, and stricturing and/or penetrating disease.53 One of the biggest
Other Disease Complications
Patients with CD colitis involving at least one-third of the colon are at an increased risk of colon cancer and require ongoing surveillance.33 If colonic disease is present, then current guidelines from the AGA recommend initiating screening 8 years after diagnosis.127 Surveillance colonoscopy is necessary only in those with more than one-third of their colon involved. This is performed every 1 to 3 years with segmental biopsies throughout the colon.127 Patients with ileal disease are also at
Conclusion
Crohn disease is a chronic IBD that can affect any portion of the gastrointestinal tract. It is typically medically managed, but a significant percentage of patients will require surgery. The goals of care are to induce and maintain a steroid-free remission, decrease the risk of complications and surgery, and also improve the overall quality of life. To this end, patients with CD are best comanaged with primary care physicians to help optimize their primary prevention and reduce their risk of
Acknowledgments
Special thanks to Martin Smith, MD, for providing the computed tomography scan images and to Robert Najarian, MD, for providing the pathology images.
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Potential Competing Interests: Dr Cheifetz is a consultant for Abbvie, Janssen Pharmaceuticals, Pfizer, Takeda, Samsung, and Miraca Laboratories. J.D. Feuerstein reports no competing interests.