Crohns Flashcards
Definition
Patchy inflammation of the GI (most common in Ileum and rectum)
Pathophysiology
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
What are granulomas
granulomas are big capsules of immune cells which are trying to incapsulate what they think is foreign.
What type of ulceration is present
Ulceration is transmural: Damage goes through the whole of the intestinal wall.
Risk factors
- Females
- Caucasian
- Jewish
- Between 20-30 and 60-70
Symptoms
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
Histology
- Non caveating granulomas
- Transmural ulceration
- Crypt accesses
- Hypertrophy of mural nerve s
- Dilation of lymph vessels
- Paneth cell metaplasia
Appearance of SI
- Ulcers- cobblestones
- Narrowing of the lumen
- Mesentery fatty and oedematous and fibrotic
- Thickened mesentery wall
- Presence of strictures
- dark serosa
Symptoms
- pain in lower right quadrant
- diarrohea- water cannot be reabsorbed
- Malabsorption
- Blood in stool from damage to SI
- Anorexia/weight loss
- Perianal disorders
- Fistulae
Differences with U.C.
- transmural
- perianal symptoms
- patchy
- granulomas
- crypt accesses less intense
- No goblet cell depletion
Consequences
- Malabsorption
- Strictures
- Fistulas
- Perforation
- Malignancy
pANCA
perinuclear antineutrophilic cytoplasmic antibody test
Positive in 75%- only positive in 25% of UC so not definitive for UC
Indications for surgery?
- 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
