IBD Flashcards
Define Inflammatory Bowel Disease. What are 3 types?
chronic relapsing idiopathic inflammation of the
gastrointestinal tract
Ulcerative colitis
Crohn’s disease
Indeterminate colitis
Describe the epidemiology of IBD. Describe teh incidence, prevalence, racial incidence, ethnic incidence, gender incidence, age at onset, and association with tobacco use of ulcerative colitis and crohns disease.
prevalence varies widely
throughout the world (>1
million in the US)
•as countries become more
developed, incidence of IBD
increases
second most common
chronic inflammatory
disorder after RA
Incidence (per 100,000)
UC:2-10
CD:1-6
Prevalence (per 100,000)
UC: 35-100
CD:10-100
Racial incidence
Caucasians = African American
Ethnic incidence
High in Jews
Gender
Male = Female
Age at onset
15-25 (? 55-65)
Tobacco
UC: More in non/previous
smokers
CD: More in smokers
What are 3 factors involved in the pathogenesis of IBD?
idiopathic disorder, mechanism not well understood
combination of
immunologic abnormalities
genetic susceptibility
environmental factors
Describe what immunologic abnormalities occur in IBD. Describe this on a cellular basis. What is the difference in the pathogen. of CD and UC?
the mucosal immune system responds against ingested
pathogens but is unresponsive to normal intestinal microflora
•IBD: disrupted mucosal immune system leading to
defects in epithelial barrier function
unregulated and exaggerated immune response against
normal flora
consequence of too much T-cell activation and/or too
little control by regulatory T lymphocytes.
Cellular Basis: antigenic triggers and intrinsic factors activate T-cells in lamina propria exaggerated immune response inflammation and epithelial damage
- differentiation of type 1 helper T cells (Th1) CD
- differentiation of type 2 helper T cells (Th2) UC
Describe some environmental factors involved in IBD
development of colitis in murine models does not occur
when they are maintained in a germ-free environment,
but develops rapidly when these mice are colonized by
commensal bacteria
some antibiotics can be helpful in Crohn’s disease
- improved sanitation is related to increased incidence of IBD
- smoking is associated with higher risk for CD
•CLIMATE
–IBD more common in cold climates
•INDUSTRIALIZED NATIONS
–IBD more common in industrialized nations
- NSAIDS
- DIET?
What is the inflammation of CD like? Where can it occur? Where is the most common site? Describe the classic histopathologic features of CD.
inflammation is transmural
•any part of the GI tract may be
involved
•most common site terminal ileum,
ileocecal valve and the cecum
•sharp demarcation between involved and uninvolved regions •skip lesions: intervening normal bowel between involved segments •Focal mucosal ulcers which coalesce later on to form long, serpentine linear ulcers along the long axis of the bowel •with intervening uninvolved mucosa between the ulcers: the mucosa acquires a cobblestone appearance
Describe some gross features of CD.
•transmural inflammation--> –Ulcers progresse to fissures between folds of the mucosa –Extension of fissures → fistulas and sinus tracts penetrating the serosa
•the intestinal wall becomes rubbery and thick due to edema, fibrosis and hypertrophy of muscularis propria -->lumen narrowing “string sign” (strictures) and obstruction
•serosa: granular and dull gray
Describe the symptoms of CD. What is the timeline like? What triggers its? How do they compare to UC?
generally more subtle as compared to UC
•intermittent attacks or progressive continuous course
•Diarrhea
Fever
abdominal pain
asymptomatic periods in between
•reactivation can be associated with stress, infection
(CMV, C. diff), NSAID’s or smoking
Describe some complications of CD.
- strictures
- fistulas
•extensive involvement of small bowel:
protein losing enteropathy weight loss malabsorption of vit B12, bile salts (steatorrhea) iron deficiency anemia Surgery for 50% to 80% of CD patients
Describe the morphology of UC.
superficial ulcerative
inflammation limited to the
colonic mucosa and submucosa
always begins in the rectum, extends proximally in a continuous fashion (no skips) then abruptly stops with a clear demarcation between involved and uninvolved areas
the small intestine is normal
mucosa: red, granular, friable and easy to
bleed with superficial broad based ulcers
no mural thickening or stricture
Progressive mucosal atrophy–> flattened and
attenuated mucosal surface
the repeated cycle of ulceration, alternating with the deposition of granulation tissue during the healing phase -->raised areas of inflamed tissue (not neoplastic): pseudopolyps
•serosal surface is completely normal
Describe the presentation and symptoms of UC.
relapsing disorder: episodes of lower abdominal pain, cramps and
bloody mucoid diarrhea persisting for variable period of time
followed by asymptomatic intervals
•
25% of patients present with constipation (proctitis)
•
severity at first presentation:
60% mild
30% moderate
10% severe/fulminant
30% patients require colectomy due to uncontrollable disease
How common is toxic megacolon in UC? Desscribe it and its presentation.
Toxic Megacolon: 5%
•colonic distension of >6 cm
signs of systemic toxicity
Usually during fist 3 months of
diagnosis
inflammatory mediators damage
the muscularis mucosa and disturb
neuromuscular function
significant risk of perforation
surgery needed in 50% of cases
List 2 opthalmic, 2 dermatologic, 3 musculoskeletal, 1 liver, and 1 oral manifestation of IBD
Ophthalmic:
Anterior uveitis
Episcleritis
Dermatologic
Erythema Nodosum
Pyoderma Gangrenosum
Muskulosceletal
Migratory polyarthritis
Sacroiliitis
Ankylosing spondylitis
Liver: PSC (primary sclerosing polyangiitis)
Aphthous ulcer (canker sores)
What is the incidence of colorectal cancer in IBD pts? What are 5 risk factors?
the cumulative incidence of colorectal cancer in ulcerative/
Crohn’s colitis patients is 5% - 13%
•
risk factors:
extent of disease duration ( >10 years) activity PSC family history of colon cancer
Review mediations
Review Medications
