Crohn's Disease Flashcards
Which of the following is NOT true of Crohn’s disease?
A) More common in Ashkenazi Jews
B) Commonly affects perianal region
C) Patchy distribution (skip lesions)
D) 5-aminosalicylic acid (5-ASA) is an effective treatment
D) 5-aminosalicylic acid (5-ASA) is an effective treatment
There is some evidence that 5-ASA medications can reduce the severity of CD disease in patients with mild to moderate disease. However, data are conflicting; therefore, the consensus is that 5-ASAs are not effective for inducing remission.
Which of the following is NOT true of Crohn’s disease?
A) Can affect any part of the GI tract
B) Surgery can be curative
C) Commonly presents with pain, diarrhoea and weight loss
D) Incidence rates are increasing
B) Surgery can be curative
Unlike UC, surgery cannot cure Crohn’s disease. This is because it can affect any part of the GI tract (and you can’t remove it all).
What are some of the common drugs used for treating Crohn’s disease?
Glucocorticoids; azathioprine; methotrexate; biological therapy; 5-ASA (this is not considered to be effective)
What non-medical treatment options are available for Crohn’s disease?
Nutritional therapy; smoking cessation’; surgery for complications (non-curative)
True or false: There is a slight female preponderance for Crohn’s disease?
True
Although incidence between M and F is very similar.
True or false: Crohn’s diagnoses are usually made around 60 years of age.
False
Both Crohn’s and UC commonly present in the twenties, with a second smaller incidence peak around 60y.
True or false: Crohn’s disease is associated with genetic defects in barrier function.
False
CD is associated with genetic defects in innate immunity and autophagy (NOD2, ATG16L1 and IRGM genes)
UC is associated with genetic defects in barrier function
True or false: Crohn’s is associated with ileal and structuring disease
True, when associated with NOD2 gene. This gene can lead to ileal and structuring disease, hence a need for resectional surgery.
True or false: Crohn’s disease is associated with a low-residue, high-refined-sugar diet?
True
Which type of inflammatory bowel disease is associated with dysbiosis (altered commensal gut microbiota)>
Both Crohn’s and UC are associated with dysbiosis.
Which sites are most commonly affected by Crohn’s disease?
- Terminal ileum and right-sided colon
- Colon alone (Crohn’s colitis)
- Terminal ileum only
- Ileum and jejunum
It is uncommon for the disease to be isolated to the perianal area.
Describe the appearance of the tissue affected by Crohn’s disease when visualised?
- Entire wall is oedematous and thickened
- Deep ulcers (linear fissures) that can form abscesses or fistulae with bowel, uterus, vagina, and skin of perineum.
- “Cobblestone” appearance to mucosa between lesions.
- Mesenteric lymphadenopathy
- Chronic inflammatory infiltrate throughout all layers of bowel wall
Why do most patients with Crohn’s disease lose weight?
- They avoid food, since eating provokes pain.
2. Malabsorption; fat, protein or vitamin deficiencies.
What are the major symptoms of Crohn’s disease?
Abdominal pain
Diarrhoea
Weight loss
What other differentials might you consider when investigating Crohn’s disease?
Key differentials: UC, infectious colitis, IBS
Others:
Bacterial infections (gastroenteritis, TB, Yersinia)
Viral infections (CMV; herpes simplex)
Amoebiasis
Non-infective: Ischaemic colitis. collagenous colitis, NSAIDs, diverticulitis, radiation proctitis, Behcet’s disease, colonic malignancy, appendicitis, PID
What are the major complications associated with Crohn’s disease?
Bowel obstruction
Malnutrition (due to malabsorption)
Toxic megacolon: bacterial toxins pass freely across the diseased mucosa of the dilated colon and into the systemic circulation via portal system.
Perforation: When the transverse colon dilates >6cm it risk perforation.
Haemorrhage: Erosion into an artery is rare but can occur.
Fistulae: Enteroenteric (diarrhoea and malabsorption), enterovesical (UTI, pneumaturia), enterovaginal (faeculant vaginal discharge). Specific to Crohn’s, does not occur in UC.
Cancer: Prolonged inflammation increases the risk of dysplasia.
What extra-intestinal complications are associated with inflammatory bowel disease?
Ocular: conjunctivitis, iritis, episcleritis
Oral: Ulcers
Derm: Erythema nodosum, pyoderma gangrenosum
Visceral: Fatty liver, liver abscess, primary sclerosing cholangitis
Thrombosis of mesenteric and portal veins
Rheumatological: Arthritis (large joints) and spondylitis (vertebrae)
What disease is being described:
“A chronic inflammatory disease characterised by transmural granulomatous inflammation affecting any part of the gut from mouth to anus (esp. terminal ileum in ~70%).”
Crohn’s disease
What are skip lesions?
A phenomenon found in Crohn’s disease (not UC) where affected patches bowel are divided by unaffected bowel.
Which section of the GI tract is most commonly affected by Crohn’s disease?
Terminal ileum (ileocaecal region)
What pattern of disease is commonly associated with Crohn’s?
Skip lesions
i.e. unaffected bowel between areas of active disease
What is the prevalence of Crohn’s disease?
100-200 per 100 000
Which disease is characterised by tissue with a cobblestone appearance, caused by deep linear ulcers forming mucosal islands?
Crohn’s disease
Which of the following are risk factors associated with Crohn’s disease?
A) White ancestry
B) Oral contraceptive pill
C) Non-smoker/ex-smoker
D) Aged 15-40/60-80
A, B and D are all correct
Smoking IS a risk factor for Crohn’s, but not for UC.
