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| Ulcerative Colitis, My Gastro room blog |
Incidence 10-20 / 100000 , more women
1 parent with UC, 6 % chance chlid with CD
If both parents have IBD, 30 % chance of the disease by 30 years
Ulcerative colitis affects the colon in a diffuse, continuous, and superficial pattern. Inflammation, which can be detected at lower gastrointestinal endoscopy, extends from the anorectal verge to a variable proximal extent.
Macroscopic features:
- Loss of vasulature
- Confluent inflammation form anal verge
- Odema, granularity and ulceration
- Purulent exudate
- pseudopolyps
Histology:
- Crypt abscesses
- Crypt shorening and brnaching and distortion
- Goblet cell depletion
- Inflammatory cell infitrate in the lamina propria
About 30% of patients exhibit immune mediated inflammatory disorders of other organs.
- Liver is affected in 5% of patients (primary sclerosing cholangitis and autoimmune liver disease),
- Joints in 20% (seronegative arthritis of the large joints, sacroiliitis, and ankylosing spondylitis),
- Eye in around 5% (scleritis, episcleritis, and anterior uveitis),
- Skin in 5% (erythema nodosum and pyoderma gangrenosum).
The exact pathophysiology is unknown, but the condition is probably caused by an inappropriate immune response to an unknown environmental stimulus within the colon.
The diagnosis is secured if inflammation of the colorectum is confirmed and colorectal epithelial biopsies show chronic changes, including crypt distortion, along with acute inflammatory changes of cryptitis, crypt abscesses, and a plasma-lymphocytoid cell infiltrate in the lamina propria.
Ulcerative colitis is a chronic lifelong disorder.
One in five patients will require sickness related absence from work or school, which impacts adversely on quality of life.
About 50% of affected people are in remission at any one time, but 90% will experience a relapsing and remitting course.
Mild to moderate flares of disease activity are often treated with oral or topical 5-aminosalicylates or oral glucocorticosteroids. These drugs inhibit production of cytokines and other inflammatory mediators, although the exact mechanisms underlying their beneficial effects in ulcerative colitis are unknown.
Glucocorticosteroids usually act within days, whereas 5-aminosalicylates may take up to four weeks to have any benefit. If there is no response to 5-aminosalicylates within two weeks, consider switching to oral glucocorticosteroids.
Some patients with difficult to control disease may benefit from combined oral and topical 5-aminosalicylates.
Severe exacerbations, characterised by the passage of at least six bloody stools a day (often with nocturnal symptoms), with systemic signs, anaemia, or raised inflammatory markers usually require admission to hospital for intravenous glucocorticosteroids.
Azathioprine, and its metabolite mercaptopurine, are the most commonly used immunosuppressants in ulcerative colitis. They are usually used in an attempt to maintain glucocorticosteroid induced remission, where 5-aminosalicylates have failed. Despite their widespread use, the evidence base to support their efficacy is not strong.
A meta-analysis of all five RCTs found a significant effect of infliximab over placebo in moderately to severely active disease.In the United Kingdom, the use of infliximab is restricted to three dose induction therapy for acute severe exacerbations.
More recent RCTs, that enrolled similarly refractory outpatient populations, have shown that adalimumab is significantly superior to placebo, although absolute differences in remission rates were modest (7-9%).The meta-analysis of RCTs of infliximab found no significant difference in adverse event rates.
Colectomy is an option for patients who do not respond to, or are intolerant of, medical treatment, or in those with complications such as colorectal neoplasia.
