Ulcerative colitis Flashcards
Define ulcerative colitis.
Chronic relapsing and remitting inflammatory disease affecting the large bowel.
How common is UC?
- 1/1500
- Higher prevelance in Ashkenazi Jews, caucasians
- Uncommon before age 10, peak onset 20-40years
- Equal sex ratio up to 40yrs then higher in males
What are the risk factors for UC?
- FH of IBD
- HLA-B27
- Infections
- NSAID use can cause flare up of disease in some
- Non-smoker or former smoker
What is the aetiology of UC?
Unknown
Suggested that:
- genetic suscpetibility (Chr12, 16)
- Immune response to bacterial/self-antigens
- Environmental factors
- Altered neutrophil function
- Abnormal epithelial cell integrity
Associated with raised serum pANCA + PSC
What part of the GI tract is affected by UC?
It may affect:
- just the rectum (proctitis, as in ~30%)
- or extend to involve part of the colon (left-sided colitis, in ~40%)
- or the entire colon (pancolitis, in ~30%).
It ‘never’ spreads proximal to the ileocaecal valve (except for backwash ileitis).
What is the pathophysiology of UC?
- Usually affects mucosa only - punctate ulcers may extend deep into the lamina propria
- Formation of crypt abscesses and a coexisting depletion of goblet cell mucin
- Hyperaemic/haemorrhagic colonic mucosa ± pseudo-polyps formed by inflammation.
- Bowel wall is generally of normal thickness - but oedema , accummulation of fat and hypertrophy of muscle layer may give it impression of thickening.
- Acute severe colitis -→ fulminant colitis or toxic megacolon (thin-walled, dilated colon that can eventually become perforated)
How is UC classified?
Left sided colitis - inflammation up to splenic flexure
Extensive colitis - inflammation beyond splenic flexure
Or Montreal classification:
- E1 (ulcerative proctitis): involvement limited to the rectum (proximal extent of inflammation is distal to the rectosigmoid junction)
- E2 (left-sided UC, also called distal UC): involvement limited to a portion of the colorectum distal to the splenic flexure
- E3 (extensive UC, also called pancolitis): involvement extends proximal to the splenic flexure.
What is the criteria for diagnosis of UC?
Truelove and Witts criteria
How do you classify mild, moderate and severe UC?
Episodic or chronic diarrhoea (± blood & mucus); crampy abdominal discomfort; bowel frequency relates to severity; urgency/tenesmus≈proctitis. Systemic symptoms in attacks: fever, malaise, anorexia, ↓weight.
What is the typical presentation of UC?
- Bloody/mucous diarrhoea (stool frequency related to severity of disease)
- Tenesmus
- Urgency
- Crampy abdo pain before passing stool
- Weight loss
- Fever
- Symptoms of extra GI manifestations - uveitis, episcleritis, erythema nodosum, pyoderma gangrenosum, arthritis, ankylosing spondylitis.
What are the signs of UC on examination?
- Signs of Fe deficiency anaemia - pallor
- Dehydration
- Clubbing
- Abdo tenderness
- Tachycardia
- Blood, mucous, tenderness on DRE
- Signs of extra GI manifestations - Clubbing; aphthous oral ulcers; erythema nodosum; pyoderma gangrenosum; conjunctivitis; episcleritis; iritis; large joint arthritis; sacroiliitis; ankylosing spondylitis; psc; nutritional deficits.
What investigations would you do for UC?
Bloods:
- FBC - low Hb, high WCC
- ESR, CRP - raised
- U&E -
- LFTs- low albumin
- Blood culture
- Serological - about 70% of patients with UC have positive pANCA; about 70% of patients with CD have positive ASCA
Stool
- Stool MC&S - infectious colitis is a Ddx
- CDT
- Faecal calprotectin - marker for disease severity
Imaging
- AXR - rule out toxic megacoon
- Flexible sigmoidoscopy/colonoscopy + rectal biopsy - determines, severity, histological confirmation, detection of dysplasia.
- Double-contrast barium enema - fine granular appearance to diffuse ulceration of bowel. NB this test may precipitate toxic megacolon
What type of endoscopy would you do in severe UC disease?
Only sigmoidoscopy in severe disease as colonoscopy has risk of perforation.
What might a colonoscopy in UC show?
- Rectal involvement,
- continuous uniform involvement,
- loss of vascular marking,
- diffuse erythema,
- mucosal granularity,
- fistulas (rarely seen),
- normal terminal ileum (or mild ‘backwash’ ileitis in pancolitis)
What is the definition of a severe attack of UC?
Definition
- Stool frequency: >6 stools/day with blood +++
- Fever: >37.5°C
- Tachycardia: >90 b.p.m.
- Erythrocyte sedimentation rate: >30 mm/h
- Anaemia: <100 g/L haemoglobin
- Albumin: <30 g/L
What is toxic megacolon?
- A serious complication of acute severe colitis
- AXR shows dilates thin walled colon with diameter >6cm
- Gas-filled and contains mucosal islands
- Impending perforation and high mortality (15-25%)
- Urgent sugery within 48hrs
- Ddx: infectious colitis e.g. C difficile, cytomegalovirus
What are the complications of UC?
GI - haemorrhage, toxic megacolon, perforation, infection, colonic carcinoma (in those with extensive disease for >10 years), gallstones, PSC (unknown aetioligy, check LFTs every year)
Extra-gastrointestinal manifestations (10-20%) - uveitis, renal calculi, arthropathy, sacroiliitis, ankylosing spondylitis, erythema nodosum, pyoderma gangrenosum, osteoporosis (from steroids), amyloidosis.
What is the management of an acute attack of UC?
Management:
- Admit
- Exclude infection
- Do endoscopy
- IV fluids
- VTE prophylaxis
- IV hydrocortisone 100 mg QDS
- Monitor: stool frequency, AXR, bloods (FBC, CRP, albumin)
Other:
- Bowel rest, parenteral feeding
- Immunosuppression - cyclosporine, 6-mercaptopurine, azathioprine, infliximab (anti-TNF monoclonal antibody)
- Monitor fluid balance and vital signs closely
- If toxic megacolon develops, low threshold for proctocolectomy and ileostomy as perforation has high mortality
What medications are used for treatment of mild-moderate UC?
- proctitis only
- procto-sigmoiditis and left-sided UC
- extensive disease
Proctitis
- topical 5-ASA (rectal mesalazine has been shown to be superior to rectal steroids and oral 5-ASA)
- if no remission in 4 weeks -→ +oral 5-ASA
- if no remission still -→ +topical /oral corticosteroid
Proctosigmoiditis and left-sided UC
- topical 5-ASA
- if no remission in 4 weeks -→ +high-dose oral 5-ASA OR high-dose oral 5-ASA + topical corticosteroid
- if no remission still -→ stop topicals, oral 5-ASA + oral corticosteroid
Extensive
- topical 5-ASA + high-dose oral 5-ASA
- if no remission in 4 weeks -→ stop topicals, high-dose oral 5-ASA + oral corticosteroid
What is the treatment of severe colitis in UC?
- IV corticosteroids 1st line (IV ciclosporin if steroids are CI)
- If no improvement after 72hrs -→ add IV ciclosporin OR consider surgery
What treatment is used for maintaining remission in mild-moderate UC?
Proctitis and proctosigmoiditis:
- topical 5-ASA alone daily OR
- topical + oral 5-ASA
- oral 5-ASA
Left-sided and extensive UC
- low dose oral 5-ASA
What is the treatment used for maintaining remission following a severe relapse or 2 or more exacerbations in the past year?
Oral azathioprine
OR oral mercaptopurine
Is methotrexate used in UC?
No (unlike in Crohn’s)
Are probiotics used in UC?
There is some evidence that probiotics may prevent relapse in patients with mild to moderate disease
