Inflammatory bowel disease - Crohn's

Question 1

IDB definition

Answer 1

Inflamed intestines, resulting in malabsorpsion

Question 2

Crohn’s defintion

Answer 2

Transmural granulomatous inflammation affecting any part of the gut from the mouth to the anus (ESP TERMINAL ILEUM ~ 70%)
There are areas of unaffected disease = NON-CONTINUOUS SKIP LESIONS

Question 3

Epidemiology

Answer 3

Jewish people
Northern European + Northern America
Females
Bimodal age = 15-40 , 50-60 years
HLA B27

Question 4

Risk factors

Answer 4

Smokers (2-4 times higher)
Family history
Stronger genetic association than UC
Chronic stress + depression = triggers flares
Diet low in fibre

Question 5

Aetiology

Answer 5

Inappropriate immune response to the gut flora in genetically susceptible individuals
- NOD-2/CARD15 mutation + env
- bacteria cause immune mediated response (T cells) = TNF a, IL1, IL6
= listeria species, mycobacteria paratuberculosis

Question 6

Pathophysiology

Answer 6

N - no blood or mucus (less common)
E - entire GI tract
S - skip lesions
T - terminal ileum (affected most, rectum usually spared + Transmural inflammation)

Crohns is assosciated with weight loss, strictures, + fistulas

Question 7

Signs

Answer 7

Abdominal tenderness
Fever
Rectal examination: blood, skin tags, erythema, fissures, fistulas, ulceration
Aphthous mouth ulcers

Question 8

Symptoms

Answer 8

Pain in RLQ
Malabsorption:
- B12/ folate def
Diarrhoea: MC in adults
Abdominal pain: MC in children
Weight loss and lethargy: non-specific symptoms
Delayed puberty in children

Question 9

Extra-intestinal manifestations

Answer 9

Arthritis (both)
Calcium oxalate renal stones
Gallstones
(both specific to crohns, and unrelated to disease activity)
Uveitis/episcleritis
Erythema nodosum/pyoderma gangrenosum

Question 10

Diagnosis

Answer 10

FIRST LINE: Bloods
- P-ANCA negative
- leucocytosis + anaemia
- CRP/ESR raised

Stool testing:
- High faecal calprotectin

GOLD STANDARD:
Colonoscopy + biopsy
- transmural inflammation
- non-caseating granulomas
- skip lesions/ cobblestone appearance

Question 11

Treatment

Answer 11

1. for flares = PREDNISOLONE
   Second line = sulfasalazine
   - severe = IV hydrocortisone
2. for remission = AZANTHIOPRINE or METHOTREXATE
3. Biologics = Anti TNF (INFLIXIMAB) + IL12 + 23 Inhibitor = USTEKENUMAB
   Surgery NOT curative

Question 12

Complications

Answer 12

FISTULA, STRICTURES, ABCESSES, SMALL BOWEL OBSTRUCTION