Amebiasis: Difference between revisions
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{{Diarrhea DDX}} | {{Diarrhea DDX}} | ||
==Evaluation== | <nowiki>Insert non-formatted text here</nowiki>==Evaluation== | ||
*CBC | *'''Labs''' | ||
*Chem | **CBC | ||
*[[LFTs]] | **Chem | ||
*Stool or abscess microscopy | **[[LFTs]] | ||
*Stool, serum, or abscess fluid antigen | **Stool PCR | ||
*Indirect hemagglutination (antibody) | ***Diagnostic gold standard | ||
*CT | ***100% sensitive and specific | ||
**Stool or abscess microscopy | |||
***<60% SN; unreliable diagnostic test<ref>Rayan HZ. Microscopic overdiagnosis of intestinal amoebiasis. J Egypt Soc Parasitol. 2005;35(3):941–951</ref> | |||
**Stool, serum, or abscess fluid antigen | |||
**Indirect hemagglutination (antibody) | |||
*'''Imaging''' | |||
**Abdominal Ultrasound | |||
***58-98% SN for liver abscess (depending on size/location) | |||
**Abdominal CT | |||
***Alternative to ultrasound; equally effective in identifying abscess | |||
==Management== | ==Management== | ||
Revision as of 02:40, 24 July 2021
Background
- Fecal oral transmission of Entamoeba histolytica cyst
- Most infection asymptomatic
- Excystation in intestinal lumen
- Trophozoites adhere and colonizes large intestine forming new cysts or invade the intestinal mucosa to cause colitis or abscesses
- Liver abscess - 10x more common in men
- Incubation period usually 2-4 weeks, but may range from a few days to years
Clinical Features
- Asymptomatic vs. dysentery vs. extraintestinal abscesses
- Intestinal- several weeks of crampy abdominal pain, weight loss, watery or bloody diarrhea
- Liver abscess-fever, cough, RUQ or epigastric pain, right-sided pleural pain or referred shoulder pain +/- GI upset
- Hepatomegaly with tenderness over the liver a typical finding
- Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity
- Extrahepatic amebic abscesses in the lung, brain, and skin are rare
Differential Diagnosis
Dysentery
- Infectious- shigella, salmonella, campylobacter, E. Coli.
- Noninfectious- Inflammatory bowel disease, ischemic colitis, diverticulitis, AV malformation.
Hepatic abscess
- Pyogenic abscess
- Aerobic: Escherichia coli, Klebsiella, Pseudomonas
- Anaerobic: Enterococcus, bacteroides, anaerobic streptococci
- Echinococcosis
- Amebiasis
- Benign cysts/malignancy
- Tuberculosis
- Mycosis
Fever in traveler
- Normal causes of acute fever!
- Malaria
- Dengue
- Leptospirosis
- Typhoid fever
- Typhus
- Viral hemorrhagic fevers
- Chikungunya
- Yellow fever
- Rift valley fever
- Q fever
- Amebiasis
- Zika virus
Acute diarrhea
Infectious
- Viral (e.g. rotavirus)
- Bacterial
- Campylobacter
- Shigella
- Salmonella (non-typhi)
- Escherichia coli
- E. coli 0157:H7
- Yersinia enterocolitica
- Vibrio cholerae
- Clostridium difficile
- Parasitic
- Toxin
Noninfectious
- GI Bleed
- Appendicitis
- Mesenteric Ischemia
- Diverticulitis
- Adrenal Crisis
- Thyroid Storm
- Toxicologic exposures
- Antibiotic or drug-associated
- Inflammatory bowel disease
Watery Diarrhea
- Enterotoxigenic E. coli (most common cause of watery diarrhea)[1]
- Norovirus (often has prominent vomiting)
- Campylobacter
- Non-typhoidal Salmonella
- Enteroaggregative E. coli (EAEC)
- Enterotoxigenic Bacteroides fragilis
Traveler's Diarrhea
- Giardia lamblia
- Cryptosporidiosis
- Entamoeba histolytica
- Cyclospora
- Clostridium perfringens
- Listeriosis
- Helminth infections
- Marine toxins
- Ciguatera
- Scombroid poisoning
- Paralytic shellfish poisoning
- Neurotoxic shellfish poisoning
- Diarrheal shellfish poisoning
Insert non-formatted text here==Evaluation==
- Labs
- Imaging
- Abdominal Ultrasound
- 58-98% SN for liver abscess (depending on size/location)
- Abdominal CT
- Alternative to ultrasound; equally effective in identifying abscess
- Abdominal Ultrasound
Management
Asymptomatic colonization
- Paromomycin or diloxanide
Colitis
Liver abscess
- Flagyl, tinidazole, paromomycin, or diloxanide
- Consider drainage of abscess by IR if no response to antibiotics in 5 days, abscess > 5cm, or left lobe involvement
Disposition
- Home if no complications