IBD - Crohn's Disease Flashcards
Define Crohn’s.
- Chronic, relapsing-remitting, non-infectious inflammatory disease of GI tract.
- Patients typically present between 20-40 years old
Describe possible aetiologies of Crohn’s.
- Still unclear
- Thought to be inappropriate immune responses to environmental triggers in genetically susceptible individuals
- 15% have family history
- Affects patient anywhere from mouth to anus - 80% have evidence of small bowel disease - most commonly in distal ileum. 25% have perianal disease
- Mixture of genetic, lifestyle and environmental factors
Describe microscopic changes of Crohn’s.
- Inflammatory infiltration, characterised by lymphoid hyperplasia
- Non-caseating granulomas.
- Transmural inflammation is also seen.
Describe macroscopic changes of Crohn’s.
- Aphthous ulcers)form due to inflammation.
- Cobblestone appearance, which can be seen on endoscopy.
- Bowel wall thickening, fistulae and fissures.
What are the risk factors for Crohn’s?
Family history
Cigarette smoking
Previous infectious gastroenteritis
NSAID usage
A diet high in refined sugar and low in fibre
List some symptoms that are typical in Crohn’s. PART 1
- Abdominal pain: most commonly in the right lower quadrant (terminal ileum) and peri-umbilical regions
- Diarrhoea: bloody or non-bloody, may be accompanied by mucus, and nocturnal diarrhoea may occur
- Perianal pain/itching: if perianal disease
List some symptoms that are typical in Crohn’s. PART 2
- Oral ulceration (aphthous ulcers)
- Nausea and vomiting
- Fever
- Fatigue
- Weight loss
Describe some extra-intestinal manifestations of Crohn’s.
- Musculoskeletal: enteropathic arthritis
- Eyes: episcleritis, uveitis and conjunctivitis
- Skin: erythema nodosum (Figure 3) and pyoderma gangrenosum
- Hepatobiliary: primary sclerosing cholangitis, fatty liver disease and gallstones
- Renal: nephrolithiasis
- Haematological: anaemia, B12 deficiency and thromboembolism
What are some typical clinical findings for someone with Crohn’s?
- Abdominal tenderness or mass
- Perianal tenderness or pain, anal or perianal skin tags, fissure, fistula or abscess
- Features of anaemia (e.g. pallor, fatigue and conjunctival pallor)
- Joint pain
- Clubbing
- Oral lesions: aphthous ulcers
What are some differential diagnoses to consider alongside Crohn’s?
Ulcerative colitis
Infectious colitis
Pseudomonas colitis
Diverticular disease
Irritable bowel syndrome (this is a diagnosis of exclusion)
Radiation colitis
What are some laboratory investigations to be done during suspected Crohn’s?
- FBC - anaemia, leucocytosis, thrombocytosis
- Liver function tests: hypoalbuminaemia
- Bone profile: hypocalcaemia
- Iron studies: normal or may demonstrate iron deficiency
- Serum B12 / folate: normal or low
- Inflammatory markers (CRP and ESR): elevated
Describe stool testing in someone with Crohn’s.
- Faecal calcoprotectin - marker of GI inflammation - distinguish IBD from non inflammatory GI conditions
- Raised in Crohn’s
- MCS needed to exclude infection
Describe the preferred methods of endoscopy in someone suspected to have Crohn’s.
- Colonoscopy and biopsy - to assess colon and terminal ileum
- Upper GI endoscopy to assess for gastroduodenal disease
List some macroscopic features of Crohn’s on endoscopy.
- Cobblestone appearance: small superficial ulcers
- Skip lesions
- Oedema
- Hyperaemia
- Aphthous ulcers
List some microscopic features of Crohn’s on endoscopy.
- Transmural involvement with non-caseating granulomas
- Lymphoid hyperplasia
Describe imaging in Crohn’s. PART 1
- Abdominal X-ray: may identify bowel dilatation and perforation in acute settings
- Abdominal ultrasound: can be used to assess bowel thickening, free-fluid or abscess formation
Describe imaging in Crohn’s. PART 2
- CT abdomen: usually used in the acute setting and to assess for complications (especially extra-mural complications)
- MRI small bowel/pelvis: can be used for ‘disease mapping’; assesses the extent of inflammation in the small bowel or fistulae formation
How is remission induced in Crohn’s?
- Corticosteroids : used to induce remission in patients with first presentation or a single inflammatory exacerbation in a 12-month period.
- Budesonide: if conventional steroid use is unsuitable, however, it is less effective.
- Aminosalicylates - cause fewer side effects than corticosteroids and budesonide but are not as effective; they are unsuitable for severe presentations.
Describe add-on treatment in someone with Crohn’s.
- Added to corticosteroid after 2 or more exacerbations in 12 month period or if corticosteroid dose cannot be reduced
- EXAMPLES: thiopurines, biologics and methotrexate
How is remission maintained in Crohn’s?
- Azathioprine
- Mercaptopurine
- Methotrexate can be used in patients who required it to induce remission
List the indications for surgical management of Crohn’s.
- Patient choice: patients with ileocaecal disease may be offered medicines or surgery
- Failure of medical management: medications do not improve disease activity or are not suitable
- Development of implications: strictures, abscesses, fistulas, obstruction or perforation
List some common surgical management options for Crohn’s. PART 1
- Strictureplasty: widens narrowed areas of the bowel that could lead to obstruction
- Fistula removal: closes, opens, drains or removes a fistula that doesn’t heal with medications
- Abscess drainage
- Colectomy: removes diseased colon, sparing the rectum
List some common surgical management options for Crohn’s. PART 2
- Proctocolectomy: removes diseased colon and rectum
- Ileostomy/colostomy
- Bowel resection: removal of the diseased small or large bowel and connection of the two healthy ends
What are the complications of Crohn’s?
- Psychosocial impact (e.g. on school, work or leisure)
- Intestinal complications: strictures, fistulas, dilation, perforation and haemorrhage
- Perianal disease
- Anaemia
- Malnutrition, faltering growth or delayed pubertal development
- Cancer of the small and large intestine
