Crohn's disease


Risk Factors

    • FHx

    • Smoking

Differential diagnosis


    • Tends to present initially in the teens and twenties, with another peak incidence in the fifties to seventies

    • Prevalence ( Northern Europe): 27–48 per 100,000

    • Higher incidence in western industrialized nations compared to other parts of the world

    • Males and females are equally affected

    • Smokers are two times more likely to develop Crohn's disease than nonsmokers.[5]

    • Genetic link


    • autoimmune disease of the gastrointestinal tract

    • Inflammation stimulated by an overactive Th1 cytokine response

    • Th17 is of greater importance in the disease?[54]

    • ATG16L1 may induce autophagy and hinder the body's ability to attack invasive bacteria

    • Increasing body of evidence in favor of the hypothesis that Crohn's disease results from an impaired innate immunity

Clinical features


    • Transmural pattern of inflammation

    • Ulceration is an outcome seen in highly active disease

    • Usually an abrupt transition between unaffected tissue and the ulcer.

    • Mucosal inflammation, characterized by focal infiltration of neutrophils into the epithelium

    • Neutrophils, along with mononuclear cells, may infiltrate the crypts, leading to inflammation (crypititis) or abscess (crypt abscess)

    • Granulomas are found in 50% of cases and are most specific for Crohn's disease

      • Do not show "caseation"

    • Biopsies may also show chronic mucosal damage, as evidenced by blunting of the intestinal villi, atypical branching of the crypts, and a change in the tissue type (metaplasia)



a) conservative

b) medical

c) surgical

    • used when partial or a full blockage of the intestine occurs