Common Crohn’s disease exam questions for medical finals, OSCEs and MRCP PACES
How does Crohn’s disease present?
- Diarrhoea (can be bloody and/or chronic)
- Abdominal pain
- Weight loss
- Malaise, anorexia, fever
- Poor growth or delayed puberty in kids
- Mouth ulcers
- Abdominal tenderness and distension
- Palpable masses
- Anal/perianal skin tags, fissures and fistulas (may be asymptomatic)
What are the extra-intestinal manifestations of Crohn’s disease?
- Erythema nodosum
- Pyoderma granulosum (purulent ulcers with blue-black edge)
What are the macro and microscopic features of Crohn’s disease?
- 20% colonic; 30% ileocaecal; 40% small bowel
- Bowel thickened and narrowed.
- Deep fissures and ulcers in mucosa, giving a ‘cobblestone’ appearance.
- Fistulae, abcesses and strictures.
- Fat wrapping around affected bits of bowel
- ‘Skip lesions’ – areas of unaffected bowel between inflamed areas.
- Mouth ulcers and anal/peri-anal disease (ulcers, fissures, fistulae)
- Full-thickness (transmural) inflammation
- Increase in chronic inflammatory cells (macrophages)
- Granulomata – not caseating
What are the complications of Crohn’s disease?
- Toxic megacolon and perforation
- Stricturing and bowel obstruction
- Small bowel cancer (if ileal involvement)
- NB. No overall increased risk of bowel cancer in IBD – only certain subgroups have increased risk (NEJM 2013)
- Iron, folate and B12 deficiencies (terminal ileum disease)
- Osteoporosis from steroid therapy
- Short-bowel syndrome and malabsorption