IBD Flashcards
What is the definition of crohn’s disease?
Chronic inflammation and ulcerating condition of the GI tract that can affect anywhere from the mouth to the anus
Where does crohn’s disease most commonnly affect?
In the terminal ileum and colon
What age group does crohn’s disease target?
Young patients
50% are 20-30 years old at diagnosis
90% are 10-40
How does crohn’s disease present?
Abdominal pain Small bowel obstruction Diarrhoea Bleeding PR Anaemia Weight loss Painful ulcers, swollen lipds, angular chielitis Peri-anal pain, abscess
What does crohn’s affected bowel look like on an endoscopy?
Cobble-stone appearance
Patchy segmental disease with skin areas (lesions) anywhere in the GI tract
What does crohn’s disease look like histologically?
Chronic inflammation in lamina propria Crypts are irregular shape Crypt abscesses Granulomas, non-causeating Giant cells Transumural inflammation Deep, knife-like fissuring ulcers
What are some common complications of crohn’s disease?
Stricturing of the bowel Bowel obstruction requiring surgery Fistulas Malabsorbtion Gallstones Anal disease Amyloidosis Toxic megacolon
What is microcytic anaemia?
Presence of small, often hypochromic, red blood cells is caused by an iron deficiency
What is macrocytic anaemia?
Red blood cells are larger than their normal volume - caused by vitamin B12 and folate deficiency
What are the environmental trggiers for crohn’s disease?
Smoking increases risk
Infectious agents
Vasculitis
Sterile environment theory
Is there is genetic link to crohn’s disease?
Yes - NOD2 on chromosome 16
What is the definition of UC?
Chronic inflammatory disoreder confined to the colon and rectum
Mucosal and submucosal inflammation
Who does UC affect?
Young patients
Peak in 3rd decade
What are the common sites of UC?
Confined to the colon and rectum
Nearly always involves the rectum
What is the presentation of UC?
Bloody diarrhoea Increased bowel frequency Urgency Tenesmus Incontinence Night rising Lower abdo pain
What is the endoscopic apprearance of UC?
Red inflamed rectum - diffusely ulcerated
Diffuse continous disease almost always involving the rectum
Pseudopolyps
What are the histological features of UC?
Diffuse mucosal chronic active colitis: massive influx of inflammatory cells
No barrier - infiltrate of inflammatory cells in the submucosa destroying the crypts
Acute cryptitis
Crypt abscesses
Sever ulceration with fibrinopurulent exudate
What are the complications of UC?
Intractable disease
Toxic megacolon
Colorectal carcinoma
Blood loss`
What are the extra-GI manifestations of UC?
Eyes: uveitis
Liver: primary sclerosing cholangitis
Joints: arthritis, ankolysing spodylitis
Skin: Pyoderma gangrenosum, erythemia nodusum
Is there a genetic link for UC?
Yes - NOD-2 on chromosome 16
What is the normal innate immunity of the gut?
Tight junctions regulate epithelial permability
Hydrophobic mucous protects epithelial cell layer
Defensins can be activated constitiively or in resposne to bacterial components
NOD2 contributes to normal mucosal defences
How does the adaptive immunity play a role in IBD?
Crohn’s - Th1 mediated
UC - Mixed Th1/Th2 mediated disease
Is there less antimicrobial activity in crohn’s or ulcerative colitis?
Crohn’s
What determines severe ulcerative colitis?
More than 6 blood stools in 24 hours and one of:
Fever, tachycardia, anaemia, elevated CRP
How is the increased risk of colorectal cancer determined?
Severity of inflammation
Duratino of disease
Disease extent (extensive colitis is beyone the splenic flexure)
What is peri-anal disease?
Recurrent abscess formation in the anus
Can lead to a fistula with persistent leakage, damaged sphincters
What are the theraputic strategies for IBD?
Lifestyle advice
Drugs
Surgery
What lifestyle can be given for crohn’s?
Smoking aggravates crohn’s and causes a wose disease outcome and a more rapif recurrence post-surgery
Diet not implicated in pathogenesis but can infleunce symptoms
What are the therapy drug options for UC?
5ASA (mesalazine)
Steroids
Immunosuppressants
Anti-TNF therapy
What are the therapy drug options for crohn’s disease?
Steroids
Immunosuppressants
Anti-TNF therapy
How does 5ASA work?
Topical effect
Anti-inflammatory properties
Reduces risk of colon cancer
Side effects: diarrhoea, idiosyncratic nephritis
How is 5-ASA given orally?
Prodrugs
pH dependent release
Delayed release
How is 5-ASA given topically?
Suppositories
Enemas
What are some examples of 5-ASA drugs?
Sulphalazine Mesalazine Asacol Pentasa Balsalazide Mezavant
What 5-ASA drug releases in all parts of the gut?
Pentasa - duodenum, jejunum, ileum and colon
What 5-ASA drug releases in the ileum and colon?
Asacol
What are steriods used for in crohn’s disease?
Systemic anti-inflammatory properties
Induces remission
Short course - high dose initially, reducing over 6-8 weeks
What are examples of corticosteroids?
Prednisolone
Budenoside
What are the muscloskeletal side effects of steroids?
Oestoporosis
Alvascualr necrosis
What are the metabolic side effects of steroids?
Weight gain
Diabetes
Hypertension
What are the cutaenous side effects of steroids?
Acne
Thin skin
What are the neurosychiartic side effects of steroids?
Cataracts
Growth failure
What should be used when a more potent suppression of inflammation is required?
UC: steroid-sparing agents
Crohn’s: maintenance therapy - azathorpine, methotrexate
What are the side effects of azathoprine?
Pancreatitis Leucopaenia Hepatits Small risk of lymphoma, skin cancer Regualr blood monitorig required
What are examples of anti-TNF therapies?
Infliximab
Adalimumab
What does anti-TNF therapy do?
Promotes apoptosis of activated T-lymphocytes
Blcoks TNF-alpha a proinflammatory cytokine
When should anti-TNF therapy be used?
As part of long term strategy, including immune suppression, surgery (crohn’s) and supportive therapy
Refractory or fistulising disease
When is surgery required in IBD?
Emergency - failure to respond to medical therapy, small bowel obstruction, abscess, fistulae
Elective: failure to respond to medical therapy, dysplasia of colon mucosae
What can repeated resection of the small intestine result in?
Short gut syndrome and requirement of lifelong total parentral nutrition
What can be done to treat peri-anal abscesses?
External drainage close to anal spincter
Can surgery for Uc be curative?
Yes, permanent ileostomy or restorative protocolectomy and pouch
What is the therapy pyramid for IBD?
Smoking cessation 5-ASA (UC) Steroids Immunosuppression Anti-TNF
