Crohn's Disease

Question 1

Where does Crohn’s disease usually occur?

Answer 1

Terminal ileum and colon.

But can occur anywhere from mouth to anus.

Question 2

What layers of the bowel are affected in Crohn’s Disease?

Answer 2

All layers down to the serosa which is why they are prone to strictures, fistulas and adhesions.

It occurs in patches..hence skip lesions.

Question 3

What are some features of Crohn’s disease?

Answer 3

• Diarrhoea: the most prominent symptom in adults. Crohn’s colitis may cause bloody diarrhoea
• Weight loss and lethargy
• Abdominal pain: the most prominent symptom in children & is usually in the lower right quadrant.
• Perianal disease: e.g. Skin tags or ulcers
• Extra-intestinal features are more common in patients with colitis or perianal disease.

Question 4

What are some extra-intestinal features of Crohn’s disease that are related to disease activity?

Answer 4

• Arthritis: pauciarticular (4 or fewer joints), asymmetric (most common in CD & UC)
• Erythema nodosum
• Episcleritis (CD>UC)
• Osteoporosis

Question 5

What are some extra-intestinal features of Crohn’s disease that are not related to disease activity?

Answer 5

• Arthritis: polyarticular, symmetric
• Uveitis (UC>CD)
• Pyoderma gangrenosum
• Clubbing
• Primary sclerosing cholangitis (UC > CD)

Question 6

Regarding management what are the appraoches that need to be considered?

Answer 6

• General points - strongly advise to stop smoking.
• Inducing Remission
• Maintaining Remission
• Surgery

Question 7

What is the drug therapy approach to inducing remission in Crohn’s disease?

Answer 7

• Glucocorticoids (oral, topical or intravenous) are generally used to induce remission. Budesonide is an alternative in a subgroup of patients
• 5-ASA drugs (e.g. mesalazine) are used second-line to glucocorticoids but are not as effective
• Azathioprine or mercaptopurine may be used as an add-on medication to induce remission but is not used as monotherapy.
  
  • Methotrexate is an alternative to azathioprine
• Infliximab is useful in refractory disease and fistulating Crohn’s. Patients typically continue on azathioprine or methotrexate
• Metronidazole is often used for isolated peri-anal disease

Question 8

Before starting on azathioprine or mercaptopurine, what do you need to assess?

Answer 8

Thiopurine methyltransferase (TPMT) activity before offering azathioprine or mercaptopurine

Question 9

What is the drug therapy approach to maintaining remission in Crohn’s disease?

Answer 9

• As above, stopping smoking is a priority (remember: smoking makes Crohn’s worse, but may help ulcerative colitis)
• Azathioprine or mercaptopurine is used first-line to maintain remission
• Methotrexate is used second-line
  
  • 5-ASA drugs (e.g. mesalazine) should be considered if a patient has had previous surgery

Question 10

What percentage of Crohn’s sufferers will need surgery?

Answer 10

80%