Crohn's Disease

Question 1

Describe the environmental factors affecting Crohn’s

Describe the genetic factors affecting Crohn’s

Answer 1

Smoking => increases risk

Enteric infections
NSAIDs
isotretinoin (acne)
ABx
Diet => simple sugars, urbanisation, microparticles, preservatives
We are too clean

NOD defect on lymphocytes => cannot differentiate between healthy and pathogenic bacteria

GREATER GENETIC COMPONENT THAN UC

Question 2

What is Crohn’s disease

-describe the epidemiology

Answer 2

Chronic inflammatory patchy transmural disease

• no gender bias
• more common in developed countries
• peak onset in 20-30s

Question 3

What are the symptoms

What is the prognosis

Answer 3

Diarrhea
RIF pain due to strictures => less likely to eat => weight loss, malnutrition, cachexic
Perianal abscess due to fistula formation (abdo mass)
Oral ulceration
Systemic symptoms

High likelihood for surgery

Question 4

Describe the pathophysiology

Answer 4

Exaggerated T cell inflammatory response to environmental factors in presence of genetically susceptible host

Question 5

How would you diagnose Crohns

Answer 5

Blood
-micro/macrocytic anemia (depending on the area affected
(proximal small bowel => Fe)
(distal ileum => B12)
-low VitD (malnutrition)
-low albumin (malabsorption of protein, loss from bowel, using up albumin in body)

Stool
-calprotectin => GI inflammatory marker

MRI, USS =>

• cobblestoning, patches of healthy, affected bowel
• strictures and fistulas

Biopsy => granulomas, transmural inflammation

Question 6

How would you manage Crohn’s

Answer 6

Acute exacerbations and maintenance of remission

ABx => ciprofloxacin, metronidazole
CHANGE GUT BIOME

Steroids => prednisolone, budesonide
AVOID WHERE POSSIBLE

Immunosuppresants => azathiopurine, mercatopurine, methotrexate

Biologics

• TNFa => infliximab, adalimumab, golimumab
• anti integrin => vedolizumab
• IL17-23 => ustekinumab

Enteral nutrition => has antiinflammatory properties, increases energy and addresses malnutrition

Question 7

Describe the surgery involved in the management of Crohns

-what do you need to keep in mind

Answer 7

Want to preserve as much bowel as possible

Drainage of perianal fistulas
-hold fistula open to allow fluid to drain out

Stricturoplasty
-removal of stricture without removing bowel

Resection of affected regions and hemicolectomies

Diverting colostomy/ileostomy => give inflammed area time to heal

Question 8

What are the extraintestinal manifestation

• during the inflammatory period
• generally

Answer 8

Inflammatory

• Eyes, mouth => conjunctivitis, iritis, episcleritis, mouth ulcers
• Liver => fatty liver, abscess, portal pyaemia
• Vasculature => portal vein, mesenteric, venous thrombosis

General

• Liver => AI
• Biliary tree => primary sclerosing cholangitis, cholangiocarcinoma, gallstones
• Renal => calcium oxalate stones, amyloidosis
• Seronegative spondyloarthropathies
• Metabolic bone disease
• Pyoderma gangrenosum, erythema nodosum