Term
| what is the most important disease involving the small intestine? |
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Definition
| crohn's disease, one of the two chronic inflammatory diseases of the GI, and the only one which can potentially involve the entire GI tract (ulcerative colitis - only in the colon) |
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Term
| how can crohns disease cause fistulas? |
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Definition
| crohns can cause transmural inflammation (penetrates through all 5 layers making up the bowel wall - mucosa, submucosa, lamina propria, muscularis propria, serosa), meaning that fistulas can eventually form from the small intestine to other organs or even the abdominal wall |
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Term
| who is affected by crohns disease? |
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Definition
| similar prevalence in all races except asians, who have a lower level of prevalence |
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Term
| what are the theorized genetic bases for crohn's disease? |
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Definition
| generally: defects w/immune response to bacteria. innately: NOD2/CARD on gene 15. adaptively: I2 w/pseudomonas, OmpC w/E. coli, CBir1 w/ CBir 1 flagellin (involves B cells and CD4 T cell response). antibody involvement: ASCA (anti saccharomyces cerevisiae ab), which no bacteria exist to justify the existence of |
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Term
| what is the major problem in crohns pts where gene 15 (NOD2/CARD) is involved? |
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Definition
| fibrostenosis/stricture formation |
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Term
| what is the major problem in crohns pts where ASCA and anti-CBir1 are involved? |
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Definition
| these correlate with very aggressive forms of crohns, and pts w/these forms often require sx (sx on crohns pts should be avoided) |
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Term
| what are the 4 types of immune response patterns in crohn's disease? |
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Definition
| type I: ASCA, type II: OmpC & I2, type III: pANCA, type IV: NO/low to any |
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Term
| what level of involvement do most crohns pts experience? |
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Definition
| distal ileum and proximal colon, however it is possible to have total mouth -> anus involvement |
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Term
| what are the characteristics of crohn's disease? |
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Definition
| inflammatory lesions w/o colonic involvement for example: pts with repeated perianal furuncles/caruncles |
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Term
| what % of crohn's pts have rectal involvement |
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Definition
| 50%, rectal involvement is more commonly seen in ulcerative colitis. if a pt presents with rectal bleeding they should be evaluated |
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Term
| what kind of lesions are characteristic to crohn's? |
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Definition
| skip lesions, which are a discontinuous pattern of inflammation that may be localized to the rectum/sigmoid - but can progress all the way to the cecum (pancolitis) |
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Term
| what is the most dependable criteria for crohns dx? |
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Definition
| epitheliod noncaseating granulomas |
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Term
| what are signs and symptoms of crohn's disease? |
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Definition
| apthous ulcers (in absence of yersinia enterocolitis), unexplained diarrhea, abdominal pain, weight loss (malabsorption due to inflammation), depression (due to lifestype changes/complications), fistuli (fistuli can be enteroenteric: intestine-intestine, enterocutaneous: intestine-skin, or enterovasicular: intestine-bladder/vagina), and obstruction (pt vomits when they eat - risk from previous sx) |
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Term
| what are physical findings associated with crohn's disease? |
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Definition
| physical: pale (Fe deficiency), weak (lack of nutrition), chronically ill, aphthous ulcers in the mouth/lips/gingival buccal mucosa, rebound tenderness, RLQ palpable mass involving SI segment, and for duodenal crohn's: stenosis, obstruction, nausea, and postprandial vomiting |
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Term
| what are lab findings associated with crohn's disease? |
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Definition
| elevated WBCs, anemia (due to malabsorption), B12 deficiency, hypoalbuminemia (due to malabsorption - can lead to peripheral edema b/c of osmotic gradient), and elevated ESR rate (more commonly seen in colon than SI) |
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Term
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Definition
| the crohn's disease activity index - used in research |
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Term
| what are serum inflammatory biomarkers associated with crohn's? |
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Definition
| CRP, an acute phase reactant which responds to increased IL-6 and TNF-alpha. it is more useful in crohns than ulcerative colitis and should be checked 1x/year. normal CRP levels may still be seen in pts with disease isolated in the ileum or w/a low BMI. |
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Term
| what are fecal inflammatory biomarkers associated with crohn's? |
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Definition
| fecal lactoferrin and calprotectin. lactoferrin is a Fe-binding glycoprotein resistant to proteolysis and can be used to distinguish between IBD and IBS (requires frozen stool). calprotectin is a Ca/Zn binding protein which is sensitive to active inflammation (but less specific for disease) and is best used in combination with lactoferrin. |
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Term
| what is the difference between genomic and genetic testing? |
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Definition
| genetic: what is inherited/predisposition. genomic: snapshot of the earliest dynamic cellular changes in response to the disease process (active form) |
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Term
| what is the natural hx of crohn's disease? |
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Definition
| relapsing/remitting disease. w/in 10 years, 60% require sx, and worse from there. the younger the age of dx, the higher the risk of sx/complicated hx - normal life expectancy, but higher risk of mortality if dx <20 yrs old. |
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Term
| when are extraintestinal complications w/crohns disease more common? |
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Definition
| when the colon is involved |
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Term
| what are the skeletal extraintestinal complications associated w/crohns disease? |
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Definition
| peripheral arthritis: usually follows disease activity, involves hips/knees/ankles, *DO NOT use NSAIDS*. axial arthritis: does not follow disease activity and may include ankylosing spondylitis (squaring of vertebrae/straightening of spine (bamboo spine) - can be crippling). sacroilitis: central type of axial arthritis, does not follow disease activity - often seen with ankylosing spondylitis or by itself. |
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Term
| what are dermatological extraintestinal findings associated with crohns? |
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Definition
| erythema nodosum - raised tender nodules on anterior lower extremities. common in children, follows disease activity - and therefore responds to bowel tx. |
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Term
| what are ocular extraintestinal findings associated with crohns? |
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Definition
| uveitis (iritis): blurred vision, photophobia, scarring/blindness possible - this is diagnosed with a split lamp and treated with local corticosteroids/atropine. episcleritis: less serious, burning eyes - treated with topical corticosteroids |
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