234.4 📌 章末速蚘

  • E. histolytica: cyst + trophozoite forms
  • Differentiate from non-pathogenic E. dispar / E. moshkovskyi (stool antigen / PCR)
  • Transmission: fecal-oral, contaminated food/water (chlorine doesn’t kill cysts)
  • Clinical:
    • 90% asymptomatic carriers
    • Acute amebic colitis (bloody diarrhea + mucus + flask ulcers)
    • Fulminant colitis (5%, peritonitis + perforation)
    • Ameboma (granulomatous mass mimicking CA)
    • Amebic liver abscess (extra-intestinal #1): RUQ pain + fever + hepatomegaly; solitary right lobe; “anchovy paste”
  • Diagnosis:
    • Stool antigen preferred (E. histolytica-specific)
    • PCR + O+P + serology (for liver abscess)
    • Imaging (US first-line for liver abscess)
  • Treatment (TWO-DRUG):
    • Tissue amebicide: metronidazole or tinidazole
    • PLUS Luminal amebicide: paromomycin (or iodoquinol)
    • Asymptomatic carrier: paromomycin alone
    • Liver abscess: + drainage if > 5-10 cm or imminent rupture or refractory
  • Pregnancy: paromomycin safe; metronidazole 1st trim avoided
  • Anchovy paste + trophozoites at periphery + no PMN = liver abscess aspirate
  • 盧醫垫 hint: endemic origin / traveler + RUQ + fever + leukocytosis → US + amebic serology + treat empirically if classic