Crohn's Disease

Question 1

Define Crohn’s Disease

Answer 1

Chronic granulomatous transmural inflammation of any part of the GI tract (mouth to anus)

Known as inflammatory bowel disease with ulcerative colitis

Question 2

Aetiology of Crohn’s Disease

Answer 2

Unknown cause

Inflammation anywhere along the GI tract, 40% in the terminal ileum

Skip lesions with inflamed segments of bowel interspersed with normal segments
Transluminal/full thickness inflammation

Question 3

Risk factors for Crohn’s Disease

Answer 3

White
15-40 or 60-80 
Family history 
Smoking 
Diet high in refined sugar 
Oral contraceptive pill
NSAIDs

Question 4

Symptoms of Crohn’s Disease

Answer 4

Abdominal pain (cramping, constant | RLQ + peri-umbilical common | relieved by defecation 
Colitis - diffuse abdominal pain 

Prolonged diarrhoea (non-bloody | May be nocturnal | colitis -> mucus, blood, pus in stool

Obstruction: bloating, distension, vomiting, constipation 
Fever 
Malaise
Fatigue 
Weight loss

Question 5

Signs of Crohn’s Disease on examination

Answer 5

Anaemia: pallor, cyanosis
Erythema nodosum
Pyoderma gangrenosum
Episcleritis: uncomfortable red eye with no loss of vision
Scleritis : painful red eye with no loss of vision
Anterior uveitis: painful red eye with loss of vision
Aphthous mouth ulceration
Arthritis
Abdominal tenderness (esp. RLQ)

DRE: perianal lesions (skin tags, fistulae, abscesses, scarring, sinuses)

Question 6

Investigations for Crohn’s Disease

Answer 6

Combo of clinical history, imaging and histology

Endoscopy/OGD/colonoscopy: mucosal oedema | ulceration (superficial AND deep) | “rose-thorn fissures” | cobblestone mucosa (patchy inflammation) | fistulae | abscesses | String sign of Kantor
Biopsy: transmural inflammation + macrophage, lymphocyte and plasma cell infiltration | Non-caseating granulomas

Stool culture: absence of infection

FBC: anaemia, leucocytosis, thrombocytosis
ESR/CRP: raised
Iron studies: may show IDA due to malabsorption/bleeding
Vit B12/folate: may be deficienct

AXR: small bowle or colonic dilation, calficiation, sacroiliitis, abscess
CT/MRI abdo: skip lesions, bowel wall thickening, inflammation, fistulae, abscess
Erect CXR: check for pneumoperitoneum (perforation)

Question 7

Management of Crohn’s Disease acute exacerbation

Answer 7

Fluid resus
IV or oral corticosteroids (hydrocortisone)
5-ASA analogues e.g. mesalazine, sulfasalazine
Analgesia

Question 8

Management of Crohn’s Disease (inducing remission)

Answer 8

1. Steroids (oral/IV ± topical) e.g. prednisolone, budesonide
2. Immunomodulator (oral/IV) e.g. azathioprine, mercaptopurine, methotrexate
3. Biological therapy (IV) e.g. adalimumab, infliximab
4. Surgery (severe, refractory, obstruction)

± nutritional therapy, perianal disease management, smoking cessation

Question 9

Management of Crohn’s Disease (maintaining remission)

Answer 9

Immunomodulators e.g. azathioprine, mercaptopurine, methotrexate

± biologics e.g. infliximab, adalimumab

± anti-spasmodics (cramp relief), anti-diarrhoeals

Question 10

What is the supportive therapy for Crohn’s Disease

Answer 10

Patient education and easy access to healthcare
Stop smoking
Dietician referral
Maintenance therapy
Antispasmodic agents - dicyloverine 20-40mg orally 3x daily when required
Antidiarrhoeal agents - loperamide 4mg orally initially, 2mg after each unformed stool max 16 mg/day

Question 11

Complications of Crohn’s Disease

Answer 11

Fistulae 
Toxic megacolon
Anaemia (iron, B12, folate)
Intestinal obstruction
Haemorrhage 
Abscess
Perforation 
Malignancy 
Bile malabsorption 

PSC 
Cholelithiasis + gallstones
Liver abscess
Hepatitis
Uveitis
Episcleritis
Amyloidosis