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
