IBD - Ulcerative Colitis Flashcards
1
Q
Define UC.
A
- Chronic IBD involving any part or all of colon and rectum
- Extends from rectum proximally
- Pathogenesis unknown - arises from interaction between genetic and environmental factors
2
Q
Describe epidemiology of UC.
A
- Presents at any age but most common in 20s to 30s
- More common in industrialised communities
3
Q
Describe pathophysiology of UC.
A
- Driven by genetic and environmental interactions - abnormal immune response to inestinal microbiome - disruption of intestinal mucosal defence barriers
- More than 200 genetic loci implicated - HLA-DQA1 variants strongly associated
- Medications can trigger onset or flare-ups e.g NSAIDs, HRT, contraceptives
4
Q
List some risk factors for UC.
A
- Family history of IBD
- Smoking - protective effect
5
Q
Describe the Montreal classification of UC.
A
- E1 - rectum only - ulcerative proctitis
- E2 - Left colon and rectum (not beyond splenic flexure) - left procto-colitis
- E3 - involvement beyond splenic flexure - extensive colitis
- E4 - whole colon as far as caecum - total colitis
6
Q
Describe the usual symptoms someone with UC would present with.
A
- Diarrhoea
- Blood in stools
- Varying degrees of abdominal pain - often none
- Weight loss
- Anaemia
- Extra-intestinal manifestations
7
Q
Describe some extra-intestinal manifestations of UC.
A
- Erythema nodosum - usually affecting lower legs
- Pyoderma gangrenosum - affecting lower limb - lateral aspect of shin, chronic and progressive, may require immunosuppressants
- Sacroilitis
8
Q
What signs may be elicited from someone with UC?
A
- Signs of anaemia, weight loss, dehydration and exhaustion
- Tenderness on abdominal palpation
- Abdominal distension with reduced bowel sounds and tympanic on percussion (suggestive of colonic dilation)
9
Q
What stool investigations would be carried out in someone suspected to have UC?
A
- Stool culture for E. coli, salmonella and clostridium dificile
- Stool sample for faaecal calprotectin level (normal 50-100 ug/g) - proteins found in neutrophils that migrate into colonic lumen - used for monitoring response to treatment - 1% of cases with symptoms consistent with IBS have IBD when level is 40 ug/g or less
10
Q
What is faecal calprotectin?
A
- Neutrophil cytosolic protein – stable for up to 7 days in faeces at room temperature
- Effective marker for the presence of intestinal inflammation (all causes)
- Simple and cost-effective way of identifying probable IBD
- FC >150ug/g warrants further investigation
11
Q
What blood tests would be carried out in someone suspected to have UC?
A
- FBC
- Inflammatory markers e.g CRP and ESR
- U&Es
- Proteins (especially albumin) and liver profile
- Vitamin D and bone profile
- Haematinic levels - iron, (B12 and folic acid)
12
Q
Describe endoscopic investigations in someone suspected to have UC.
A
- Flexible sigmoidoscopy usually sufficient, due to distal nature of UC
- Full colonoscopy may be required if findings on sigmoidoscopy are unclear.
- Colonoscopy must be avoided in acute severe disease due to the increased risk of bowel perforation.
13
Q
Describe histological investigations in someone suspected to have UC.
A
- At least two biopsies from each lower bowel segment (eg rectum, sigmoid, descending etc) even when it looks normal
- No diagnostic histological features but plasmacytosis, crypt distortion and irregularity of the mucosal surface with polymorph infiltration are very suggestive
- Presence of granulomas strongly suggests Crohn’s
14
Q
Describe disease management in someone suspected to have UC.
A
- First – induce clinical remission (ie normalization of bowel movements and cessation of bleeding)
- Second – maintain steroid-free remission
- Choice of drug(s) - determined by severity of presenting symptoms
- “Step-up” or “Top-down” approach - dependent on severity and extent of disease activity
15
Q
Describe some medical managements of UC. PART 1
A
- Aminosalicylates - Mesalazine-5-aminosalicylic (5-ASA) is the current first-line treatment of choice for induction and maintenance of remission of mild-to-moderate UC.
- Corticosteroids e.g prednisolone are typically used to induce remission in relapses of ulcerative colitis. Not used to maintain remission
