Acute and chronic inflammation of the GIT Flashcards
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 3 categories of cases 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
How do NSAID’s cause acute inflammation?
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 though pathogenesis?
- What are the symptoms
- large bowel only. Starts in rectym , extends proximally
- continuous, mucosal inflammation, granulomas absent
- though 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 to disease activity - 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
Surgical management of UC
Crohns
- treatments of complications e.g. perianal disease, fistulae
- segemental resections
- high risk of disease in remaining bowel
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
thickeness - transmural/mucosal distribution - mouth to anus/large bowel pattern - skip lesions/continuous histology - non-caseating granulomas/crypt abscesses fistulae - common/rare strictures - common/rare perianal disease - common/rare
Coeliac disease:
- What is it?
- What are the complications?
- What are the clinical features
- How is it diagnosed?
- Management?
- gluten sensitive enteropathy with associated villous atrophy
- malabsorption of iron, folate, calcium, fats, amino acids
- often normal, weight loss, diarrhoea, pathos ulceration, anaemia
- anti tissue-transglutaminase antibody and anti-endomysial antibody
endoscopic duodenal/jejunal biopsy - villous atrophy - avoid gluten, majority get mucosal recovery, poor adherence increases risk of GI lymphoma
