Inflammatory Bowel Disease

Crohn Disease“terminal ileitis” or “regional enteritis Lecture 12 by Dr Mohammad Manzoor Mashwani BKMC Mardan

IIBD- Crohn’s DiseaseCrohn’s Disease (CD)

• Crohn’s Disease is an idiopathic, chronic, transmural inflammatory process of the bowel that can affect any part of the gastro intestinal tract from the mouth to the anus.

• Most cases involve the small bowel, particularly the

terminal ileum.

InflammatoryChronic RelapsingAutoimmune ?Idiopathic

A systemic inflammatory disease with predominant intestinal involvement.

IBDcomprised of two major disorders:

Ulcerative Colitis (UC)

Crohn’s Disease (CD)

99

Burril

Bernard

Crohn

Epidemiology• Higher number of cases of Crohn’s disease found in western

industrialized nations. • Males and females are equally affected. • Smokers are three times more likely to develop Crohn's

disease.• Crohn's disease tends to present initially in the teens and

twenties (Young adults).

Classification of CD On the area of the gastrointestinal tract which it affects:

• Ileocolic Crohn's disease: Affects both the ileum and the large intestine (50%)

• Crohn's ileitis: Affects the ileum only (30%)

• Crohn's colitis: Affects the large intestine, accounts for the remaining twenty percent of cases.

Classification of CD

On the behavior of disease as it progresses:

• Stricturing disease causes narrowing of the bowel which may lead to bowel obstruction or changes in the caliber of the feces.

Stricturing

Classification of CD• Penetrating disease creates abnormal passage ways between the

bowel and other structures such as the skin.

• Inflammatory disease causes inflammation without causing strictures or fistulae.

Inflammatory Penetrating

They result from an abnormal local immune response against the normal flora of the gut, and probably against some self antigens, in genetically susceptible individuals.

The pathogenesis of IBD involves genetic susceptibility, failure of immune regulation, and triggering by microbial flora.

Morphology Location: (Any) terminal ileum, ileocecal valve, and cecum. Multiple, separate, sharply

delineated areas of disease, resulting in skip lesions/patchy/cobblestone appearance. The intestinal wall is thickened and rubbery as a consequence of transmural edema, inflammation, submucosal fibrosis, and hypertrophy of the muscularis propria, all of which contribute to stricture formation.

aphthous ulcer-serpentine ulcersFissures, fistula ,perforation. mesenteric fat frequently extends around the serosal

surface (creeping fat) Clusters of neutrophils within a crypt (crypt abscesses) destruct crypt leading to distortion of mucosal architecture; the normally straight and parallel crypts take on bizarre branching shapes and unusual orientations to one another. Epithelial metaplasia- gastric antral-appearing glandscalled pseudopyloric metaplasia. Paneth cell metaplasia may also occur in the left colon, where Paneth cells are normally absent. Noncaseating granulomas, a hallmark of Crohn disease, are found in approximately 35% of cases. Granulomas may also be present in mesenteric lymph nodes. Cutaneous granulomas form nodules that are referred to as metastatic Crohn disease.

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Morphology• Location-any- terminal ileum, ileocecal valve, cecum• Lesion- skip, patchy; stricture formation; serpentine ulcer;• Fissure, fistula, perforation; creeping fat; crept abscess-

distortion of mucosal architecture; pseudopyloric metaplasia; Noncaseating granulomas.

A granuloma is a focus of chronic inflammation consisting of a microscopic aggregation of

macrophages that are transformed into epithelium-like cells, surrounded by a collar of mononuclear leukocytes, principally lymphocytes and occasionally plasma cells.

Granuloma is a collection macrophages.

Gross pathology of Crohn disease. A, Small-intestinal stricture. B, Linear mucosal ulcers and thickened intestinal wall. C, Perforation and associated serositis. D, Creeping fat.

Microscopic pathology of Crohn disease. A, Haphazard crypt organization results from repeated injury and regeneration. B, Noncaseating granuloma. C, Transmural

Crohn disease with submucosal and serosal granulomas (arrows).

Common symptoms of Crohn's disease:• abdominal pain• diarrhoea• weight lossLess common symptoms include:• poor appetite• fever, night sweats• rectal pain/rectal bleeding Some patients with Crohn's disease also develop symptoms outside of

the gastrointestinal tract; these symptoms include:• arthritis• skin rash• inflammation of the iris of the eye.

Symptoms- Extremely variablePositive String SignAge: 15-30 periods of flare-ups and remission,

Approximately 20% of patients present acutely with right lower quadrant pain, fever, and bloody diarrhea that may mimic acute appendicitis or bowel perforation. Periods of active disease are typically interrupted by asymptomatic periods that last for weeks to many months.

Disease re-activation can be associated with a variety of external triggers, including physical or emotional stress, specific dietary items, and cigarette smoking.

Smocking is a strong exogenous risk factor for development of Crohn disease and, in some cases, disease onset is associated with initiation of smoking. Unfortunately, smoking cessation does not result in disease remission.

Iron-deficiency anemia may develop in individuals with colonic disease, while extensive small bowel disease may result in serum protein loss and hypoalbuminemia, generalized nutrient malabsorption, or malabsorption of vitamin B12 and bile salts.

Fibrosing strictures, particularly of the terminal ileum, are common and require surgical resection.

Disease often recurs at the site of anastamosis, and as many as 40% of patients require additional resections within 10 years.

Fistulae develop between loops of bowel and may also involve the urinary bladder, vagina, and abdominal or perianal skin.

Perforations and peritoneal abscesses are common.

sacroiliitis, ankylosing spondylitis, erythema nodosumclubbing of the fingertips,

Risk of colonic adenocarcinoma is increased in patients with long-standing colonic disease.

Paper Question Annual 2013

• A young emotionally stressed female presents to medical OPD with complaints of intermittent attacks of mild diarrhea, abdominal pain and fever followed by asymptomatic period lasting for weeks and months. Positive String sign is seen. Colonoscopy reveals patchy, deep intestinal ulcers. Continue on next slide…..

• a. What is the most likely diagnosis? 1• b. How would you differentiate the diagnosis

from other form of Irritable Bowl Disease (IBD)? 6

• c. What are the main factors that contribute to the above diagnose disease? 3