Inflammatory bowel disease: Crohn's disease Flashcards
What is Crohn’s disease?
Crohn’s disease is a form of inflammatory bowel disease that commonly affects the terminal ileum and colon but may occur anywhere from the mouth to anus.
What is the cause of Crohn’s disease?
The cause is unknown, but there is a strong genetic susceptibility.
What layers of the gastrointestinal tract are affected by Crohn’s disease?
Inflammation occurs in all layers, down to the serosa.
What complications are patients with Crohn’s disease prone to?
Patients are prone to strictures, fistulas, and adhesions.
What percentage of Crohn’s disease patients have small bowel involvement?
80% of patients have small bowel involvement, usually in the ileum.
What are the common presentations of Crohn’s disease?
Common presentations include weight loss, lethargy, diarrhea, abdominal pain, and perianal disease.
What is the most prominent symptom of Crohn’s disease in adults?
Diarrhea is the most prominent symptom in adults.
What is the most prominent symptom of Crohn’s disease in children?
Abdominal pain is the most prominent symptom in children.
What investigations are commonly performed for Crohn’s disease?
Investigations include raised inflammatory markers, increased faecal calprotectin, anemia, and low vitamin B12 and vitamin D.
What are common extra-intestinal features of Crohn’s disease?
Common features include arthritis, erythema nodosum, episcleritis, and osteoporosis.
What type of arthritis is most common in Crohn’s disease?
Pauciarticular, asymmetric arthritis is related to disease activity.
What extra-intestinal feature is more common in Crohn’s disease than in ulcerative colitis?
Episcleritis is more common in Crohn’s disease.
What extra-intestinal features are unrelated to disease activity?
Unrelated features include polyarticular, symmetric arthritis, uveitis, pyoderma gangrenosum, clubbing, and primary sclerosing cholangitis.
Which extra-intestinal feature is much more common in ulcerative colitis?
Primary sclerosing cholangitis is much more common in ulcerative colitis.
Which extra-intestinal feature is more common in ulcerative colitis than in Crohn’s disease?
Uveitis is more common in ulcerative colitis.
What is Crohn’s disease?
Crohn’s disease is a form of inflammatory bowel disease that commonly affects the terminal ileum and colon but may be seen anywhere from the mouth to anus.
What blood test correlates well with Crohn’s disease activity?
C-reactive protein correlates well with disease activity.
What is the investigation of choice for Crohn’s disease?
Colonoscopy is the investigation of choice.
Features suggestive of Crohn’s include deep ulcers and skip lesions.
What histological features are associated with Crohn’s disease?
Inflammation in all layers from mucosa to serosa, goblet cells, and granulomas.
What is the role of small bowel enema in Crohn’s disease?
It has high sensitivity and specificity for examination of the terminal ileum.
Strictures may present as ‘Kantor’s string sign’, proximal bowel dilation, ‘rose thorn’ ulcers, and fistulae.
What is Crohn’s disease?
Crohn’s disease is a form of inflammatory bowel disease that commonly affects the terminal ileum and colon but may be seen anywhere from the mouth to anus.
What guidelines were published for the management of Crohn’s disease?
NICE published guidelines on the management of Crohn’s disease in 2012.
What general advice should be given to patients with Crohn’s disease?
Patients should be strongly advised to stop smoking. Some studies suggest an increased risk of relapse secondary to NSAIDs and the combined oral contraceptive pill, but the evidence is patchy.
What is the first-line treatment to induce remission in Crohn’s disease?
Glucocorticoids (oral, topical, or intravenous) are generally used to induce remission.
What alternative medication may be used in a subgroup of patients to induce remission?
Budesonide is an alternative in a subgroup of patients.
What dietary approach may be used to induce remission?
Enteral feeding with an elemental diet may be used in addition to or instead of other measures to induce remission, particularly if there is concern regarding the side-effects of steroids.
What second-line medication is used to induce remission?
5-ASA drugs (e.g. mesalazine) are used second-line to glucocorticoids but are not as effective.
What medications may be used as add-on therapy to induce remission?
Azathioprine or mercaptopurine may be used as an add-on medication to induce remission but are not used as monotherapy. Methotrexate is an alternative to azathioprine.
What is the role of infliximab in Crohn’s disease?
Infliximab is useful in refractory disease and fistulating Crohn’s. Patients typically continue on azathioprine or methotrexate.
What is often used for isolated peri-anal disease?
Metronidazole is often used for isolated peri-anal disease.
What is the priority for maintaining remission in Crohn’s disease?
Stopping smoking is a priority.
What is the first-line medication used to maintain remission?
Azathioprine or mercaptopurine is used first-line to maintain remission.
What should be assessed before starting azathioprine or mercaptopurine?
+TPMT activity should be assessed before starting.
What is used second-line to maintain remission?
Methotrexate is used second-line.
What percentage of patients with Crohn’s disease will eventually have surgery?
Around 80% of patients with Crohn’s disease will eventually have surgery.
What surgical procedure is performed for stricturing terminal ileal disease?
Ileocaecal resection.
What is the investigation of choice for suspected perianal fistulae?
MRI is the investigation of choice for suspected perianal fistulae.
What is a draining seton used for?
A draining seton is used for complex fistulae to keep the fistula open.
What is required for a perianal abscess?
Incision and drainage combined with antibiotic therapy.
What are some complications of Crohn’s disease?
Patients are at risk of small bowel cancer, colorectal cancer, and osteoporosis.
What is the standard incidence ratio for small bowel cancer in Crohn’s disease?
Standard incidence ratio = 40.
What is the standard incidence ratio for colorectal cancer in Crohn’s disease?
Standard incidence ratio = 2.
What are the two main types of inflammatory bowel disease?
Crohn’s disease and ulcerative colitis.
What are some common symptoms of Crohn’s disease?
Diarrhoea usually non-bloody, weight loss more prominent, upper gastrointestinal symptoms, mouth ulcers, perianal disease, and abdominal mass palpable in the right iliac fossa.
What are some common symptoms of ulcerative colitis?
Bloody diarrhoea more common, abdominal pain in the left lower quadrant, and tenesmus.
What extra-intestinal manifestation is more common in Crohn’s disease?
Gallstones are more common due to reduced bile acid reabsorption.
What complications are associated with Crohn’s disease?
Obstruction, fistula, and colorectal cancer.
What complications are associated with ulcerative colitis?
Higher risk of colorectal cancer compared to Crohn’s disease.
Where can lesions be seen in Crohn’s disease?
Lesions may be seen anywhere from the mouth to anus, with skip lesions present.
Where does inflammation start in ulcerative colitis?
Inflammation always starts at the rectum and never spreads beyond the ileocaecal valve.
What histological features are seen in Crohn’s disease?
Inflammation in all layers from mucosa to serosa, increased goblet cells, granulomas.
What histological features are seen in ulcerative colitis?
No inflammation beyond submucosa (unless fulminant disease), depletion of goblet cells and mucin from gland epithelium, granulomas are infrequent.
What endoscopic findings are characteristic of Crohn’s disease?
Deep ulcers, skip lesions, and ‘cobble-stone’ appearance.
What endoscopic findings are characteristic of ulcerative colitis?
Widespread ulceration with preservation of adjacent mucosa, which has the appearance of polyps (‘pseudopolyps’).
What radiological findings are associated with Crohn’s disease?
Small bowel enema showing strictures, proximal bowel dilation, ‘rose thorn’ ulcers, and fistulae.
What radiological findings are associated with ulcerative colitis?
Barium enema showing loss of haustrations, superficial ulceration, and ‘pseudopolyps’.
Which extra-intestinal manifestation is much more common in ulcerative colitis than in Crohn’s disease?
Primary sclerosing cholangitis (82%).
