Crohn disease Flashcards
definition of crohn’s
inflammatory bowel disease,
mostly affects young adults and adolescents between the ages of 15 and 35
second peak at 60 years
m>f
whites and jews
located in the terminal ileum, but can discontinuously (skip lesion) affect the entire gastrointestinal tract
eads to complications such as fistulas, abscesses, and stenosis
linical features include diarrhea, weight loss, and abdominal pain in the right lower quadrant (RLQ), as well as extraintestinal manifestations in the eyes, joints, or skin.
difficult to diagnose because there is no confirmatory test
Acute episodes rx w/ corticosteroids,
severe cases,: immunosuppressants
Crohn disease cannot be cured!!! (in contrast to ulcerative colitis). The goal of treatment is thus to avoid the progression and recurrence of inflammatory episodes.
what causes crohn’s dusease
balance between proinflammatory and anti-inflammatory mediators from unknown cause
Nicotine consumption is the only (known) controllable risk factor for Crohn disease.
RF
1)Nicotine abuse
-Nicotine consumption is the only (known) controllable risk factor f
2) Familial predisposition -mutation of the NOD2(all ppl w/ CD have nod2 but not all pl w/ NOD2 mutation have CD)
- HLA-B27 association
pathophys of CD
Unknown mechanisms (possibly NOD2) lead to the activation of lymphatic cells (Th1) in the intestinal walls
→ inflammation
→ local tissue damage (edema, ulcers, necrosis) → obstruction
d/2 fibrotic scarring, stricture, and strangulation of the bowel
pathophys of abscess & fistulae
intestinal aphthous ulcers form → transmural fissures and inflammation of intestinal walls → adherence to other organs or skin → penetration of adjacent organs/skin → microperforation →abscess formation or → macroperforation into these structures → fistula formation
where does crohn’s disease
usually terminal ileum/ colon or entire GI stystem from mouth to anus in skip leasion manner
SPARES RECTUM
how may NOD2 mutation increase risk of CD
1)loss of function mutations in NOD2
→ allow bacteria to enter the intestinal mucosa
→ cause an unregulated inflammation
2)Dysfunctional NOD2
→ cause overactivity of the NF-κB signaling pathway
→ ↑ production of pro-inflammatory cytokines and antimicrobial peptides
→ chronic autoinflammation
sx of CD
non-bloody, chronic diarrhea (micro bleeding w/ occult blood causes iron def anemia!!)
Abdominal pain, typically in the RLQ
malabsoprtion sx
- failure to thrive
- vitb12 def ( inflamed terminal ileum)
sx d/2 reduced bile acid absorption in intestines
- -def of fat sol vit
- -gallstones
- -kidney stones(d/2/ excess ffa d/e/ loss of bile acids, Ca2 binds to ffa instead of oxalate, oxalate accum in kidney and stone forms)
abscesses & enterocutaneous fistula between ileium and perianal reion (FIRST SIGNS)
bowel obstruction
peirtonitis d/2 perforation
extraintestinal sx of CD
Joints: enteropathic arthritis (e.g., sacroiliitis)
Eye: iritis, episcleritis, uveitis
skin diseases;
-Erythema nodosum
(inflammation of subcutaneous fat caused by a delayed hypersensitivity reaction)
-Acrodermatitis enteropathica
(Zinc deficiency may cause bullous skin abrasions, especially on the hands, feet, and genital area. not specific for crohn’s)
Pyoderma gangrenosum ( very painful, rapidly-progressive, red spots that can change into purulent pustules or deep ulcerated lesions with central necrosis)
oral apthae
dg of CD
Laboratory tests
1) Blood
- inflamm markers↑ CRP, ↑ –ESR, ↑ thrombocytes, and ↑ leukocytes
- Anemia
- ↑ ASCA (Anti-Saccharomyces cerevisiae mannan antibodies for UC dx)
Feces
Stool analysis to rule out gastroenteritis caused by bacteria
occult blood
IMAGING -axr -barium swallow String sign ( inflammation and fibrosis may narrow the intestinal lumen in other sections) Creeping fat
US: see abscesses/fistulas
Endoscopy confirms the diagnosis, assesses the extent of the disease, differentiates CD from other diseases
HISTOLOGY: Non-caseating granulomas & Giant cells
which sign on barium swallow is pathognomic for CD
creeping fat: Proliferated mesenteric fat between the intestinal loops is pathognomonic for CD.)
Ileocolonoscopy findings
typical segmental/ discontinuous involvment of intestines (skip lesions)
Linear/transmural ulcers (snail trails)
aphthous hemorrhagic mucosa
Cobblestone sign: characteristic appearance of Inflamed sections followed by deep ulcerations that resemble uneven cobblestones
rx of CD (no cure)
general rx
- nicotine asbstinence
- lactose freee diet d/2 2ndairy lactase def
- vit su for mmalabsoprtion
- excacerbation:avoid dietary fibre & parenteral nutrition
pharmacotherapy w/ step up therapy// top down therapy -antidiarrhoea med(loperamide) -systemic corticosteriods (prednisone) -immunosuppresents if steroids fail (tnf alpa ab's (infliximab)// methotrexate)
surgery(aims to resect non func/ damaged intestines but preserve overall func/health
- ileostomy, ileocolostomy, colectomy,proctocolectomy
- abscess:percutaneous drainage/ surgical drainage of
- fistula: fistulectomy
indications of surgery in CD
Failed medical therapy
Severe complications abscesses, perforation, toxic megacolon, obstruction, stricture, hemorrhage
why do pt w/ cronh’s need freq check ups e/ endoscopy
increased risk of colorectal carcinoma and/or recurrence of the disease
complications of crohn’s
colorectalcarcinoma
short bowel sx after surgery
osteoporosis
reduced growth!
fistula’s (3)
- enterocutaneous fistulas: inestinal content on skin
- gasstrocolic fistulas: weight loss. abd pain, foul burps
- rectovaginal fistula: stool via vag
- aortoenteric fistula: rectal bleed
