Inflammatory Bowel Disease Flashcards
Pathophysiology
Genetic Factors
- Appears to be genetically linked, although no specific gene has been identified
- Genetically susceptible pts are unable to clear infecting pathogens and unable to downregulate immune responses appropriately leading to chronic, relapsing intestinal inflammation (Immunologic dysfunction)
Environmental Influences
- Does not exist in developing countries so environmental influences are though to be important, but are poorly understood
Risk Factors
Higher Socioeconomic populations
Jewish population–esp. Ashkenazi
Urban areas
Bimodal age of presentation–if present later in life tend to be easier to tx
Location of IBD
UC:
- involves the rectum and extends proximally continuously
- Can be rectosigmoid, extending beyond sigmoid, or pan-colitis
- lesions are mucosal or submucosal
Crohn’s
- MC site is terminal ileum, but can be anywhere
- Rectum is often spared
- Characterized by skip lesions (discontinuous)
- Inflammation is transmural, and bowel wall can become thickened, fibrotic, and strictured
Symptoms of IBD
UC:
- Diarrhea
- tenesmus, urgency
- rectal bleeding/bloody stool
- mucous
- pain in LLQ
Crohn’s:
- Vary more because depends on location
- RLQ pain more common
- diarrhea, but less bloody than UC
Complications of IBD
(intraintestinal)
UC
- Toxic megacolon: severe inflammation causing gross dilation of colon–> risk of perforation and peritonitis
- Hemorrhage: uncommon
Crohn’s
- Stenosis: may lead to bowel obstruction or stasis with subsequent bacterial overgrowth
- Fistulas: enteroenteric, enterovesicular, rectovaginal
- Malabsoprtion if extensive ileal disease: B12, may see weight loss, bile salt diarrhea
Both UC and CD are at increase risk of CRC
Extraintestinal manifestations (6)
Hepatobiliary:
- PSC: bile duct inflammation and fibrosis that can progress to biliary cirrhosis or liver failure. Most pts who have PSC also have IBD, but reciprocal isn’t true.
- Cholelithiasis: form because malabsorption of bile acids, resulting in depletion of the bile salt pool and the of lithogenic bile
Rheumatologic
- Peripheral arthritis from inflammation–reversible
- Ankylosing spondylitis–hips and back stiffness. Continuous and progressive
Occular
- Iritis and uveitis–emergency
Derm
- erythema nodosum
- aphthous stomatitis-mouth ulcerations (CD)
**Urologic **
- Nephrolithiasis
Thromboembolic state so more likely to throw clot
PE and Lab Dx
PE:
- Assess pts nutritional and volume status
- Eye and oral exams
- GI: abdominal exam (distention), BS changes, tenderness, rebound, mass
- Rectal: tender anal canal, blood on exam
- MSK: swollen, tender joints
Lab:
- Inflammation markers: CRP and ESR
- CBC-anemia from bleeding, leukocytosis
- Stool: culture for bacteria, fecal lactoferrin (sensitive and specific for intestinal inflammation)
- Serologies can be used to differentiate between UC and CD–not to dx or track progression
Endoscopic Findings
UC:
- diffuse erythema, friable appearance
CD:
- Cobblestoning from submucosal edema
Radiographic studies
AXR
- assess for complications like toxic megacolon or SBO
CT
- Can verify the presence and location of inflammation
- Monitor for complications (SBO, abscesses, fistulas, or perforations)
CT or MR enterography (special contrast)
- used first line for CD
- clearly shows mural thickening/inflammatory changes in SB
IBD Tx
Non-Pharm:
- lmt caffein and gas producing vegetables
- Vitamin supplements if malabsorption
- Parenteral nutrition in severe exacerbations to prevent growth delay in children
Pharm: Top Down Therapeutic Approach
- First: Immunodulators or Biologics (Anti-TNF aka Remicade): tx aggressively to reduce complications and then back down to maintain.
- Can also use 5-ASA PO or PR and corticosteroids
- Surgical tx: Proctocolectomy is curative in UC. CD use bowel resection to remove strictures, abscesses, etc. or disease that does not respond to tx
Celiac Sprue Pathophysiology
T cell mediated gluten intolerance in genetically predisposed individuals
Wheat, barley, or rye induces characteristic lesion that resolves with gluten withdrawal
Celiac Sxs
Symptoms depend on severity and location of disease
- Asymptomatic
- N/V/D/C
- Abdominal pain
- Weight loss
Celiac Labs
Findings can be broad, maybe see:
hypoalbuminemia
iron deficiency
transaminitis
TTG–pretty sensitive and specific
Celiac Endoscopy
Duodenum appears scalloped or atrophic
Biopsies show blunted villi
Celiac Tx
Gluten Free Diet
