UC Flashcards
definition of UC
relapsing and remitting inflammatory disorder of the colonic mucosa
aetiology of UC
inappropriate immune response against ?abnormal colonic flora in genetically susecptible people
Th1 Th2 and Th17 response
innate immune system
suggested hypotheses
- genetic suseptibility
- immune response to bacterial or self antigens
- env factors
- altered neutrophil function
- abnormality in epithelial cell integrity
RF for UC
positive FH of IBD
associated with increased serum pANCA, PSC, other autoimmune diseases
epidemiology of UC
100-200/100000 prevalence
10-20/100000/yr incidence
typically presents 20-40yrs, second peak 50-60
3x more common in non-smokers - start when stop smoking
sx of UC
may effect just the rectum (proctitis, 30%) +- part of colon (L sided colitis 40%) or the entire colon (pancolitis, 30%)
never spreads prox to ileocecal valve - except for backwash ileitis
episodic or chronic diarrhoea +- blood and mucus
crampy abdo discomfort
bowel freq relates to severity of disease
urgency/tenesmus = proctitis
systemic symptoms: fever, malaise, anorexia, reduced weight
signs of UC
may be none
in acute, severe: may be fever, tachycardia, tender distended abdo
clubbing
aphthous oral ulcers
erythema nodosum
pyoderma gangrenosum
conjunctivitis
episcleritis
iritis
large joint arthritis
sacroileitis
ankylosing spondylitis
PSC
nutritional deficits
blood mucus and tenderness on PR
signs of IDA, dehydration
pathology of UC
sharp demarcation
hyperaemic/haemorrhagic colonic mucosa +- pseudopolyps (areas of non-ulcerated swollen mucosa) formed by inflammation.
Punctuate ulcers might extend into the lamina propria,
not transmural.
Continuous inflammation limited to the mucosa
In severe pan-colitis, ileocaecal valve is damaged and fixed open = “backwash ileitis” - inflammatory exudate from the colonic mucosa = minor inflammation in the last section of ileum.
acute and chronic inflammatory cells in lamina propria, inflamed areas are contiguous, crypt abscesses (neutrophils in colonic glands), cell dysplasia if long history
criteria for acute severe colitis
Frequency of stool >6
Overtly bloody stool
Fever (>37.5)
Tachycardia (>90)
Anaemia (Hb<105)
Raised ESR (>30)
ix for uc
bloods
- FBC - low Hb, high WCC
- ESR, CRP high
- low albumin
- U&E
- LFT
blood culture
stool: MC&S/CDT - exclude campylobacter, c diff, salmonella, shigella, e coli, amoebae – exacerbations of IBD caused by infection. Rule out infectious colitis
calprotectin - GI inflammation, high sensitivity
abdo x ray - no faecal shadows, mucosal thickening/islands, colonic dilatation, rule out toxic megacolon
lower GI endoscopy - lower flexible sigmoidoscopy if acute to assess and biopsy, full colonoscopy once controlled to define disease extent - determines severity, histological confirmation, detection of dysplasia
barium enema - mucosal ulceration with granular appearance and filling defects (pseudopolyps), featureless narrow colon, loss of haustral pattern (leadpipe/hosepipe appearance)
radiolabelled white cell scan - highlights area of bowel inflammation
Mx of UC
induce and maintain remission
mild:
- 5-ASA eg mesalazine is for remission-induction/maintenance - PO or PR
- topical steroid (hydrocortiosone as colifoam) or prednisolone enemas (predsol)
moderate: 4–6 motions/day, but otherwise well - induce - oral prednisolone 40mg, then taper for 7wks
- maintain - 5-ASA
- monitor FBC and U&E at start, then at 3 months, then annually
severe: unwell and >=6 motions/d
- IV hydration/electrolyte replacement;
- IV steroids, eg hydrocortisone 100mg/6h or methylprednisolone 40mg/12h;
- rectal steroids, eg hydrocortisone 100mg in 100mL 0.9% saline/12h PR;
- thromboembolism prophylaxis
- AB
- multiple stool MC&S/CDT - exclude infection
- Monitor T°, pulse, and BP, record stool frequency/character on a stool chart
- Twice-daily exam: distension, bowel sounds, tenderness.
- Daily FBC, ESR, CRP, U&E±AXR
- Rescue therapy with ciclosporin or infliximab, can avoid colectomy
- if improving - prednisolone PO 40mg/24hr, maintenance infliximab if used for rescue or azathioprine if ciclosporin rescue
- if fail to improve - urgent colectomy by day 7-10
- bowel resection if toxic megacolon - perforation mortality 30%
SE of 5-ASA
rash,
haemolysis,
hepatitis,
pancreatitis,
paradoxical worsening of colitis
advice for UC pts
patient eductation and support,
treatment of complication,
regular colonoscopic surveillance
markers of UC activity
low Hb, low alb, high ESR or CRP
bleeding,
fever
and diarrhoea frequency
- <4 per day = mild,
- 4–6 per day = moderate,
- >6 per day = severe
maintenance of UC
5-ASA
consider other immunosuppressants eg cyclosporin, azathioprine
when do you use immunomodulation for UC
patients flare on steroid tapering or require 2 or more courses of steroids a year eg azathioprine 2-2.5mg/kg/d PO
30% of patients get SEs requiring treatment cessation: abdominal pain, nausea, pancreatitis, leucopenia, abnormal LFTS.
Monitor FBC, U+E, LFT weekly for 4 wks, then every 4 wks for 3 months, then at least 3-monthly.
