Crohns Flashcards
What is crohns disease
It is a chronic inflammatory bowel disase which can occur anywhere along the GI tract
Usually presents around 15-30 years old and has another peak in adulthood at 60-80 years old
Has a remitting and relapsing course
Where does crohns most commonly affect
Targets the distal ileum or proximal colon
What are the macroscopic features of Crohns disease
transmural inflammation
Skip lesions throughout the bowel
produces deep ulcers an fissures - cobblestone appearance
Fistulas can form due to the inflammation being transmural and going all the way through the wall
What are the microscopic changes in Crohns disease
Granulomas - non caseating
What are the main risk factors for Crohns disease
Family hx
Smoking - increases risk of developing crohns
White european descent - esp Ashkenzi Jews
Appendicectomy
What are the clinical features of Crohns disease
Abdominal pain and diarrhoea - episodic Abdo pain can be colicky in nature Systemic symptoms - malaise - weight loss - anorexia - low grade fever - if malnourishment severe in children may present as failure to grow/thrive - signs of dehydration
Oral ulcers
Perianal disease - skin tags, perianal abscesses, fistulae and bowel stenosis
What are the extra-intestinal features of Crohns disease
MSK: Large joint arthritis
Ankylosing Spondylitis
metabolic bone disease - secondary to malabsorption
Skin:
Pyoderma gangrenosum - typically affect the shins, erythematous papules/pastules that develop into deep ulcers
Erythema nodosum - tender red/purple subcutaneous nodules typically found on shins
Eyes:
Uvetitis (more common in UC)
Episcleritis
Hepatobiliary: Gallstones - secondary to reduced bile reabsorption
Primary sclerosing cholangitis - more common in UC
Cholangiocarcinoma
Renal:
Oxalate renal stones - due to reduced bile salts reabsorption so more free oxalate
Which investigations are done in suspected Crohns
Bedside Obs Bloods - FBC --> anaemia and WCC count - CRP - raised - LFTs - U+Es - may show dehydration
Stool sample x3 = faecal calprotectin
Stool sample for MC+S for potential infective cause
Blood cultures may be taken to rule out infective cause if very unwell
Imaging - AXR –> exclude toxic megacolon or bowel obstruction
Colonoscopy with biopsy - gold standard, cobblestoning of bowel - SHOULD BE AVOIDED DURING ACUTE FLARE - increased risk of perforation
Barium swallow - can show strictures and the string of Kantor
CT scan - warranted in severe Crohns disease
For perianal disease - MRI pelvis
How is remission induced in Crohns disease
Aggressive fluid resuscitation
Nutritional support
Prophylactic heparin - prothrombotic state in IBD flares
Corticosteroids
immunosuppressants - mesalazine and aziothioprine
How is remission maintained in Crohns disease
Smoking cessation
Azathioprine or Mercaptopurine - as monotherapy
Biological agents e.g. infliximab if failure of treatment with other agents
What further management can be offered to Crohns patients
Support from specialist IBD nurses and patient support groups
Enteral nutritional support should be considered in young patients with growth concerns
Colonoscopic surveillance offered to people who have had the disease for >10 years with >1 segment of bowel affected
What is the most common surgical treatment for Crohns
Ileocaecal resection - removal of terminal ileum and caecum through primary anastamosis between ileum and ascending colon
What are the complications of Crohns disease
Strictures - causes obstruction
Fistulas - colovesical, colovaginal, enterocutaenous, perianal
Perianal abscesses
GI malignancy
Malnutrition
Osteoporosis
Increased risk of gallstones and renal stones
