Crohns

Question 1

Definition

Answer 1

Patchy inflammation of the GI (most common in Ileum and rectum)

Question 2

Pathophysiology

Answer 2

Autoimmune character:
-Excessive response to microbiota in the Gut
-The inflammatory response to these pathogens is so great it leads to damage to the cell epithelium
-Pathogens are able to cross the intestinal wall as it is damaged.
-This triggers an inflammatory response
pANCA antigens - Perinuclear antineutrophillic cytoplasmic antibodies
-As more cells are damaged the immune response moves further deeper Into the intestinal wall and lead to granulomatous inflammation and eventually ulceration

Question 3

What are granulomas

Answer 3

granulomas are big capsules of immune cells which are trying to incapsulate what they think is foreign.

Question 4

What type of ulceration is present

Answer 4

Ulceration is transmural: Damage goes through the whole of the intestinal wall.

Question 5

Risk factors

Answer 5

• Females
• Caucasian
• Jewish
• Between 20-30 and 60-70

Question 6

Symptoms

Answer 6

ain- usually lower right quadrant

• Diarrhoea: damaged tissue results in less water being absorbed
• Blood in stool: from damaged tissue.
• Malabsorption- if SI involved
• Anorexia/ Fatigue
• Perianal symtoms- not in UC
• Fistulae

Question 7

Histology

Answer 7

• Non caveating granulomas
• Transmural ulceration
• Crypt accesses
• Hypertrophy of mural nerve s
• Dilation of lymph vessels
• Paneth cell metaplasia

Question 8

Appearance of SI

Answer 8

• Ulcers- cobblestones
• Narrowing of the lumen
• Mesentery fatty and oedematous and fibrotic
• Thickened mesentery wall
• Presence of strictures
• dark serosa

Question 9

Symptoms

Answer 9

• pain in lower right quadrant
• diarrohea- water cannot be reabsorbed
• Malabsorption
• Blood in stool from damage to SI
• Anorexia/weight loss
• Perianal disorders
• Fistulae

Question 10

Differences with U.C.

Answer 10

• transmural
• perianal symptoms
• patchy
• granulomas
• crypt accesses less intense
• No goblet cell depletion

Question 11

Consequences

Answer 11

• Malabsorption
• Strictures
• Fistulas
• Perforation
• Malignancy

Question 12

pANCA

Answer 12

perinuclear antineutrophilic cytoplasmic antibody test

Positive in 75%- only positive in 25% of UC so not definitive for UC

Question 13

Indications for surgery?

Answer 13

• Failure of meds
• Need to relieve obstruction of SB
• To manage fistulae
• To manage abdominal abcesses
• To manage anal fissures, accesses, fistulas and skin tags