Inflammatory Bowel Disease Flashcards
What is inflammatory bowel disease?
Umbrella term for idiopathic inflammatory chronic conditions UC and Crohn’s
What is ulcerative colitis?
Type of IBD characterised by diffuse (continuous) inflamm of colonic mucosa. Has relapsing, remitting course.
Can be anywhere from colon to rectum.
Only innermost layer affected (mucosa)
What is Crohn’s disease?
Type of IBD characterised by transmural inflammation of GIT. May involve any or all parts, from mouth to anus.
Skip lesions.
Can occur in all layers of bowel.
Layers of large bowel?
4 layers (from lumen outward):mucosa, submucosa, muscular layer, and serosa
Muscular layer made up of 2 layers of smooth muscle: inner circular layer and outer longitudinal layer
Pathophysiology of ulcerative colitis?
Most cases in rectum, w some developing terminal ileitis
Oedema, accumulation of fat, and hypertrophy of muscle layer→ impression of thickened bowel wall.
Only involves mucosa
Formation of crypt abscesses and depletion of goblet cell mucin.
Undermining of mucosa + excesses granulation tissue→ inflammatory polyps/ pseudopolyps.
What is proctitis (in context of ulcerative colitis)?
When inflammation limited to rectum
Aetiology of ulcerative colitis?
Unclear
- Genetic predisposition
- Potentially autoimmune, initiated by inflammatory response to colonic bacteria
Risk factors for ulcerative colitis? (3 main)
Family Hx of IBD
HLA B27
Infection
Weak:
- NSAID use
- Not smoking or former smoker
Signs and symptoms of ulcerative colitis?
- Subacute onset <2 w
- Rectal bleeding and blood in stool
- Diarrhoea
- Diffuse abdominal pain and tenderness
- Spondylitis and arthritis
- Malnutrition and dehydration
- DRE: blood and mucus on glove
Uncommon: fever, weight loss, rash, uveitis
Ix: Non-imaging investigations for ulcerative colitis?
Stool study: negative culture and C. diff toxins A and B; WBC present
Faecal calprotectin: elevated
- Elevated w bowel inflamm. Useful in supporting differential of IBS vs IBD
FBC: variable degree of anaemia, leukocytosis, or thrombocytosis
ESR: high/ normal
Low B12 and folate
High pANCA
Ix: What is a pANCA test? (ulcerative colitis)
Testmeasures amount of peripheral antineutrophil cytoplasmic antibodies (p-ANCA) in blood (ABs to neutrophils)
Ix: Imaging investigations (and respective results) for ulcerative colitis?
Abdominal XR:
- Thumbprinting
- Toxic megacolon (over 6cm diameter)
- Dilated loops
- Double contrast barium enema “lead pipe appearance”
Flexible unprepared sigmoidoscopy: acute
Flexible sigmoidoscopy/ colonoscopy: not acute
- Continuous erythema
- Ulceration
- Crypt abscess
- Loss of vascular marking
- Mucosal granularity
Biopsies: obtained during endoscopy
- Continuous distal disease, mucin and goblet cell depletion, diffuse mucosal atrophy, absence of granulomata, and anal sparing
Acute management for ulcerative colitis?
Nutritional support
Manage extra-intestinal manifestations
Corticosteroids (IV/ oral hydrocortisone, severity-dependent)
Hospital admission if acute and severe
IV fluids, and analgesia
ABs
Ciclosporin/biologicals
When is surgery done for acute management of ulcerative colitis?
Toxic megacolon (proctosigmoidectomy and ileostomy) or failure to respond to steroids in 48h
Colectomy (3rd line)
Management for ulcerative colitis when trying to maintain remission?
Mild: 5-ASA (aminosalicyclates- reduce inflammation of intestine) + biologics
Severe: immunomodulators + biologics
Surgery: if medical fails and complications
Potential complications of ulcerative colitis? (6)
- Toxic megacolon
- Perforation
- Massive haemorrhage
- Colon cancer
- PSC (primary sclerosing cholangitis)
- Cholangiocarcinoma (ca19-9 diagnostic tumour marker)
What is primary sclerosing cholangitis?
Disease of bile ducts. In PSC→ inflamm scars within bile ducts.
Signs and symptoms inclu: intermittent abdominal pain (under ribs/ pinching pain RUQ), diarrhoea, jaundice, fever, fatigue
Pathophysiology of Crohn’s disease?
Inflamm + ulceration→ non-caseating granulomas
Granulomas involve all layers of intestinal wall and mesentery and regional lymph nodes
Lesions separated by normal bowel mucosa discontinuously (skip lesions)
Aetiology of Crohn’s disease?
Unclear
Suggested environmental and genetic factors
- Genetic susceptibility and heritable risk
- Smoking, OCP, NSAIDs, diet, Campylobacter infections
Risk factors for Crohn’s disease?
White ethnicity
Age 15-40/ 50-60 (bimodal age dist)
Fam Hx of CD
Weak:
- Cigarette smoking, low fibre diet
- OCP, NSAIDs
Signs and symptoms of Crohn’s disease?
- RLQ (or peri-umbilical) abdominal pain
- Abdominal tenderness
- Prolonged diarrhoea (may be bloody)
- Perianal lesions (skin tags, fistulae, abscesses, scarring, etc)
- Bowel obstruction
- Fever and fatigue
Uncommon: weight loss, arthropathy, erythema nodosum, ocular signs (inclu uveitis)
Ix: Standard tests (non-imaging) done for Crohn’s disease?
FBC, iron studies, B12 and folate, metabolic panel, ESR and CRP
May show anaemia, leukocytosis, thrombocytopenia; low/ normal iron; low/ normal B12/ folate (may be secondary to malnourishment); hypoalbuminaemia, hypocholesterolaemia, hypocalcaemia; elevated ESR/ CRP
DRE exam (PR bleed)
Stool test (Check for infections, esp C.difficile if recent AB use)
Ix: Imaging investigations for Crohn’s disease and possible findings?
Abdo XR (or CT)
- Part of initial tests
- Skip lesions, bowel wall thickening, surrounding inflamm, abscess, fistulae
ACUTE: Flexible unprepared sigmoidoscopy
NOT ACUTE: Ileocolonoscopy + biopsy
Conservative management done for Crohn’s disease?
- Stop smoking
- Nutritional advice
- Manage peri-anal abscess
- Refer to MDT to manage extra-intestinal manifestations (steroids)
Medical management for INDUCING remission, for Crohn’s disease?
Prednisolone/biologics (e.g. infliximab)
- Steroids - osteoporosis, immunosuppression, hirsutism
Medical management for MAINTAINING remission, for Crohn’s disease? (and their potential side effects)
Immunomodulators (azathioprine) + biologics
- Azathioprine - can cause bone marrow suppression, non-melanoma - Methotrexate - must monitor LFTs, injection weekly + folate - liver fibrosis, bone marrow suppression, can't be taken during pregnancy - Infliximab = TNF alpha inhibitor - myelosuppression, reactivation of TB and Hep B
When is surgical management used for Crohn’s disease and what might it involve?
Failure to thrive and medication not working
Surgical resection (consider carefully)
If obstructive symptoms, may consider: surgery/ dilation
Potential complications of Crohn’s disease? (3)
Extra-intestinal involvement
Intestinal obstruction
Abscess/ fistulae formation
