What are the distinguishing features of ulcerative colitis?
(young adult females)
- inflammation of rectum & variable extent of colon
- continuous spread (distal -> proximal)
- mucosa has TH2 phenotype (produces TGF-alpha & IL-5)
- gross bleeding in ALL cases
- peri-anal disease rare
- no fistulas formed
- no granulomas formed
What is inflammatory bowel disease? What is it caused by? What conditions come under IBD?
Idiopathic inflammation of the GI tract
Causes:
- ?genetic predisposition
- ?environmental factors
- ?immunological factors
Triggered by altered microflora e.g. antibiotics, diet, acute infection, NSAIDs, smoking, stress
- ulcerative colitis
- Crohn’s disease
- indeterminate colitis
- other colitides e.g. microscopic colitis, diversion colitis, diverticular colitis, pouchitis
What are the distinguishing features of Crohn’s disease?
(15-30yrs & ~60yrs)
- inflammation potentially along entire GI tract (mouth -> anus)
- discontinuous spread (normal-abnormal-normal)
- mucosa has TH1 phenotype (produces gamma-interferon & IL-2)
- ~25% have gross bleeding
- ~75% have peri-anal disease
- fistulas formed
- granulomas formed in ~50%-75%
What are the endoscopic features of ulcerative colitis?
- aphthous ulcers rare
- surrounding mucosa is abnormal
- longitudinal ulcers rare
- no cobble-stone ulceration
- mucosal friability common
- vascular pattern distorted
What are the endoscopic features of Crohn’s disease?
- aphthous ulcers common
- surrounding mucosa is relatively normal
- longitudinal ulcers common
- cobble-stone ulceration in rare cases
- mucosal friability uncommon
- vascular pattern normal
What are the pathological features of ulcerative colitis?
- transmural inflammation uncommon
- fissures rare
- fibrosis does not occur
- submucosal inflammation uncommon
- pseudopolyps
What are the pathological features of Crohn’s disease?
- transmural inflammation
- fissures common
- fibrosis common
- submucosal inflammation common
What are the radiological features of ulcerative colitis?
- collar button ulcers (barium going under mucosa)
- bowel looks straighter
What are the radiological features of Crohn’s disease?
- nodularity
- granularity
- cobble stone ulceration
- string sign of Kantor (narrow & dilated areas of bowel look like a string of pearls)
What are the histological features of ulcerative colitis?
Non-specific signs of acute inflammation:
- oedematous lamina propria (acute)
- neutrophil infiltration —> crypt abscess (acute)
- distorted crypt architecture (chronic)
- crypt atrophy (chronic)
- chronic inflammatory infiltrate
What are the histological features of Crohn’s disease?
- microgranulomas
- epithelioid granulomas
What is an aphthous ulcer?
Benign, non-contagious ulcer found in mouth
What is a pseudopolyp?
Island of normal mucosa surrounded by atrophic mucosa
What is the treatment for inflammatory bowel disease?
- aminosalicylates (reduce inflammation)
- corticosteroids (reduce inflammation, more potent than ASAs)
- immunosuppressants
- ileostomy (small intestine diverted to hole in abdomen)
- ileo-anal pouch (part of small intestine used to create internal pouch connected to anus - stools can be passed normally)
