Infection, Inflammation and the Gut Flashcards Preview

Gastoenterology > Infection, Inflammation and the Gut > Flashcards

Flashcards in Infection, Inflammation and the Gut Deck (13):

What are the features of Giardia infection?

- Waterborne protozoal infection

- Associated with immunodeficiency

- Treated with metronidazole


What are the features of C. difficile?

- Often prior to treatement with antibiotics (e.g. Clindamycin)

- Causes elimination of gut commensals and overgrowth of toxin producing C. difficile

- Diagnosed by finding toxin in the stool

- Treated with vancomycin


What causes Whipple's disease and how is it diagnosed?

- Infection by Tropheryma

- Diagnosed on biopsy of duodenum - PAS positive macrophages


What are the features of Entamoeba Histolytica Infection?

- Intestinal amebiasis may involve any part of the bowel

- Small foci of necrosis that progress to ulcers

- Flask-shaped ulcer with narrow neck and broad base

- May metastasize to the liver


What does M. Tb do to the GIT?

- Granulomatous inflammation with confluent granulomas, usually with caseous necrosis

- Loss of crypts

- Fibrin and acute inflammatory cells present

- Endoscopic findings include strictures, ulcers and mucosal hypertrophy


What is tropical sprue a histological mimic of and how is it treated?

- Coeliac disease

- Treat with tetracycline


What are the features of Coeliac disease?

- Diagnosed on duodenal biopsy whilst on gluten-containing diet

- Histology supports other features (coeliac-assocated antibodies, HLA-DQ2 and/or DQ8, response to gluten exclusion)


What are the histopathological features of coeliac disease?

- Villous atrophy

- Crypt hyperplasia

- Increased number of intraepithelial lymphocytes

- Increased numbers of plasma cells in lamina propria


What are the features of ulcerative colitis?

- Peak age of onset 15-25

- Gradual onset of chronic bloody diarrhoea >4 motions per day

- Rectum always involved

- Inflammation confined to mucosa and submucosa of large intestine

- Crypt architectural distortion (irregular)

- Crypt abscess (≥4 neutrophils in a crypt)

- Complications include acute toxic dilatation, perforation and increased risk of carcinoma of the colon


What are the features of Crohn's disease?

- Commonly presents 15-35 years

- Commoner in smokers

- Can affect any part of gut from mouth to anus

- Commonly affects terminal ileum

- Inflammation commonly transmural

- Granulomas are diagnostic

- Mutations in NOD-2 are associated

- Fistulae between the intestine and other intestinal loops, skin, bladder, vagina


What are the features of diverticular disease of the colon?

- Principally affects sigmoid colon

- Low roughage diet causes constipation and high sigmoid luminal pressure – herniation of mucosa through weaknesses in muscle coat of sigmoid

- Presents with left iliac fossa pain

- May perforate, fistulae into bladder or bowel, bleed, or obstruct bowel


What are the causes of ischaemia of the gut?

- Mesenteric artery or vein thrombosis

- Mesenteric artery embolus

- Hypotension (watershed infarction)

- Strangulated hernia

- Volvulus


How is gut ischaemia diagnosed?

- Endoscopy will show petechial haemorrhages, oedematous and fragile mucosa, segmental erythema, scattered erosion, longitudinal ulcerations, sharply defined segment of involvement