Acute and chronic inflammation of the GIT Flashcards
What are the 3 types of acute infectious diarrhea (gastroenteritis)?
- Inflammatory or bloody diarrhea
- Non inflammatory diarrhea
- food poisoning
What are the causes of acute infectious diarrhea?
- Emotional stress
- food intolerance
- organic substance- mushrooms, shellfish
- drugs (NSAIDs)
- infectious agents
- Chemical- alcohol, bleach
What are 3 categories of causes of acute inflammation of the GIT? Give examples within each.
- drug induced e.g. NSAID’s
- chemical e.g. alcohol, bleach
- infections (gastroenteritis) e.g. salmonella, campylobacter, clostridium difficile
What are the characteristics of acute inflammation?
- lasts only a few days
- usually a precipitating factor e.g. infection, noxious chemical
- cell infiltrate mostly neutrophils, eosinophils
- minimal tissue damage
- healing and recovery
What are the 6 categories of chronic diarrhea
- osmotic
- secretory
- inflammatory
- malabsorptive
- chronic infections
- motility disorders
What is the effect of NSAIDs on GIT?
- inhibt COX-1 and COX-2
- COX-2 reduces inflammation which is the desired effect
- But also inhibits COX-1 which produces prostaglandins important in mucosal protection of the stomach
- This leads to gastric ulcers
What are the characteristics of chronic inflammation?
- prolonged
- can progress from acute
- mixed inflammatory cell infiltrate
- tissue destruction - necrosis
- remodelling of tissue - fibrosis granuloma formation
What are three categories of chronic inflammation, give examples of each
- IBD e.g. crohns and UC
- coeliac disease
- others e.g bechet’s, systemic sclerosis
Crohn’s Disease:
- Where can there be inflammation?
- What are the defining characteristics of this inflammation?
- What does it appear to be due to? What is the evidence for this?
- What are the symptoms?
- Anyway in the GIT, more in terminal ileum, then colon, then perianal, then other areas
- transmural inflammation (full thickness), skip lesions, non-necrotising granulomas
- abnormal response or lack of tolerance to bacterial pathogens. lymphocyte transfer in transgenic mice - no colitis
- diarrhoea, abdo pain, weight loss, anorexia, pyrexia, fistulae
Ulcerative Colitis:
- Where can there be inflammation?
- What are the characteristics of this inflammation?
- What is the thought pathogenesis?
- What are the symptoms
- large bowel only. Starts in rectum , extends proximally
- continuous, mucosal inflammation, granulomas absent
- thought to be secondary to abnormal response to bacterial or food allergen
- bleeding, diarrhoea, pain, tenesmus, faecal urgency
What are some extra intestinal manifestations of Crohns and UC?
- related to disease activity
- usually related
- unrelated
- Related
- apthous ulceration -mouth ulcers
- eruthema nodosum -fatty lump on shin
- arthropathy - pain in joints in absence of inflammation
- episcleritis - inflammed sclera
- Usually related
- pyoderma gangrenosum - gangrenous ucler on leg
- anterior uveitis - eyes, blindness
- Unrelated to colitis
- sacroilitis
- ankylosing spondylitis
- primary sclerosing cholangitis
- cholangiocarcinoma
What are some IBD investigations
blood tests:
- full blood count
- urea and electrolytes
- liver function
- C reactive protein (CRP) - inflammatory marker
stool:
- c difficile
- other pathogens
abdominal xray, Sigmoidoscopy, colonoscopy, small bowel imaging, histology, capsule endoscopy
Medical management of IBD
induce remission:
- steriods -oral/IV
Maintenance: modulate immune response
- aminosalicylates
- purine analogues
- calcineurin inhibitors
- anti-TNF alpha antibodies
Surgical management of Crohn’s
Crohns
- treatments of complications e.g. perianal disease, fistulae
- segmental resections
- high risk of disease in remaining bowel
Surgical management of UC
UC
- sub-total colectomy with end ileostomy
- panproctocolectomy with ileo-anal pouch
- permenant cure possible
What are the differences between Crohn’s and UC in terms of:
- thickness
- distribution
- pattern
- histology
- fistulae
- strictures
- perianal disease
