Crohn's disease and Ulcerative colitis Flashcards Preview

Module 104: Theme 1 > Crohn's disease and Ulcerative colitis > Flashcards

Flashcards in Crohn's disease and Ulcerative colitis Deck (19)
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1
Q

Epidemiology of Crohn’s disease

A

Highly prevalent in Western world

Biomodal presentation

  • Peaks in teens/20s
  • Peaks in 60-70
2
Q

Genetics of Crohn’s disease

A

Strong genetic predisposition

Frameshift mutation in NOD2 gene

  • The gene is responsible for inhibiting immune response to luminal microbes
  • Mutation causes uncontrolled inflammation
3
Q

Infectious cause of Crohn’s disease

A

Mycobacterium paratuberculosis

  • Due to presence of granulomas
  • Not completely proven
4
Q

Environmental factors for Crohn’s

A

Improved hygiene hypothesis
- Mucosa not immunised to microbes.

Migrating from a low to high risk population

Smoking ciagarettes

5
Q

Clinical presentation of Crohn’s

A

Abdominal pain relived by opening bowel

Chronic courses with periods of remission and relapses

Prolonged non-bloody diarrhea

Weight loss

6
Q

Distribution of Crohn’s in the GI

A

Can affect anywhere from the mouth to anus:

  • Mainly small bowel alone
  • Affects large bowel and small+large equally
7
Q

Morphological features of Crohn’s

A

Fat wrapped around serosa

Segmented inflammation- skipped lesions

Ulceration forms cobblestone pattern

Strictures formed from fibrosis

8
Q

Microscopic appearance of Crohn’s

A

Transmural inflammation of bowel

Mixed inflammation:

  • Chronic and acute
  • Contains polymorphs and lymphocytes

Crypts are preserved

Fissuring ulcers

Granuloma common in 60-65% of cases

Fibrotic gut wall.

9
Q

Complications from Crohn’s

A

Fistulas from deep ulcers

Sinus tract- blind ended tract

Obstruction from adhesions and strictures

Perianal fistula and sinuses

Risk of adenocarcinoma (lower than UC)

10
Q

Epidemiology of Ulcerative colitis

A

Most common in western countries

Rare before age 10.

  • Peaks 20-25
  • Smaller peak 55-65
11
Q

Environmental factors and UC

A

Smoking is protective

Exacerbated by NSAIDs

Possibly associated with low Vit a and E

12
Q

Clinical features of UC

A

Intermittent bloody diarrhea/ mucoid diarrhea

Abdominal pain

Weight loss

Low grade fever

13
Q

Macroscopic features of UC

A

Affects any part of large bowel only:

  • Proctitis (rectum only)
  • Left bowel
  • Total colitis

No ulcers in early disease

Bowel shortens and mucosa flattens

14
Q

Microscopic features of UC

A

Inflammation of the mucosa ONLY

Mixed inflammation

Crypt architecture distortion

15
Q

Complications of UC

A

Toxic megacolon- very dilated bowel

Refractory bleeding

Dysplasia/ adenocarcinoma

16
Q

Ocular extra-intestinal presentation of CD and UC

A

Uveitis

Iritis

Episcleritis

17
Q

Cuntaneous extra-intestinal presentation of CD and UC

A

Erythema nodosum

Pyoderma gangrenosum

18
Q

Investigations for CD and UC

A

C-reactive proteins

Endoscopy and biopsy

Radiological imaging

  • Barium
  • MRI
  • USS
  • CT
19
Q

Differences between CD and UC

  • Obstruction
  • Fistula
  • Weight loss
  • Perianal disease
  • Distribution
  • Pathology
  • Cancer risk
  • Smoking
A

Obstruction
- More common in CD

Fistula:
- Seen in CD but not UC

Weight loss:
- Common in CD, not as much in UC

Perianal disease:
- Much more common in CD

Distribution:

  • CD affects anywhere in the gut in skipped lesions.
  • UC only affects large bowel continuously

Pathology:

  • UC is mucosal only with no ulcers, granulomas
  • CD is transmural with fissuring ulcers, granulomas
  • Crypts are distorted in UC but preserved in CD.

Cancer:
- UC has higher risk that CD

Smoking:
- Makes CD worse, but UC better.