Amebiasis: Difference between revisions
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==Background== | ==Background== | ||
*Fecal oral transmission of Entamoeba histolytica cyst | *Fecal oral transmission of Entamoeba histolytica cyst | ||
*Most infection asymptomatic | |||
*Excystation in intestinal lumen | *Excystation in intestinal lumen | ||
*Trophozoites adhere and colonizes large intestine forming new cysts or invade the intestinal mucosa to cause colitis or abscesses | *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 | *[[Liver abscess]] - 10x more common in men | ||
*Incubation period usually 2-4 weeks, but may range from a few days to years | |||
==Clinical Features== | ==Clinical Features== | ||
*Asymptomatic vs. dysentery vs. extraintestinal abscesses | *Asymptomatic vs. dysentery vs. extraintestinal abscesses | ||
*Intestinal- several weeks of crampy abdominal pain, weight loss, watery or bloody diarrhea | *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 | *[[Liver abscess]]-[[fever]], [[cough]], [[RUQ pain|RUQ]] or [[epigastric pain]], right-sided [[chest pain|pleural pain]] or referred shoulder pain +/- GI upset | ||
**Hepatomegaly with tenderness over the liver a typical finding | **[[Hepatomegaly]] with tenderness over the liver a typical finding | ||
**Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity | **Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity | ||
*Extrahepatic amebic abscesses in the lung, brain, and skin are rare | *Extrahepatic amebic abscesses in the lung, brain, and skin are rare | ||
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==Differential Diagnosis== | ==Differential Diagnosis== | ||
===Dysentery=== | ===Dysentery=== | ||
*Infectious- | *Infectious- [[shigella]], [[salmonella]], [[campylobacter]], [[E. Coli]]. | ||
*Noninfectious- [[Inflammatory bowel disease]], [[ischemic colitis]], [[diverticulitis]], AV malformation. | *Noninfectious- [[Inflammatory bowel disease]], [[ischemic colitis]], [[diverticulitis]], AV malformation. | ||
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*CBC | *CBC | ||
*Chem | *Chem | ||
* | *[[LFTs]] | ||
*Stool or abscess microscopy | *Stool or abscess microscopy | ||
*Stool, serum, or abscess fluid antigen | *Stool, serum, or abscess fluid antigen | ||
*Indirect | *Indirect hemagglutination (antibody) | ||
*CT or ultrasound for suspected abscess | *CT or ultrasound for suspected abscess | ||
==Management== | ==Management== | ||
===Asymptomatic colonization=== | ===Asymptomatic colonization=== | ||
*[[Paromomycin]] or | *[[Paromomycin]] or diloxanide | ||
===Colitis=== | ===Colitis=== | ||
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===Liver abscess=== | ===Liver abscess=== | ||
*[[Flagyl]], [[tinidazole]], [[paromomycin]], or diloxanide | *[[Flagyl]], [[tinidazole]], [[paromomycin]], or diloxanide | ||
*Consider drainage of abscess if no response to antibiotics in 5 days, abscess > 5cm, or left lobe involvement | *Consider drainage of abscess by IR if no response to antibiotics in 5 days, abscess > 5cm, or left lobe involvement | ||
==Disposition== | ==Disposition== | ||
*Home if no complications | *Home if no complications | ||
==References== | ==References== | ||
<references/> | <references/> | ||
Revision as of 18:56, 29 September 2019
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
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
Evaluation
- CBC
- Chem
- LFTs
- Stool or abscess microscopy
- Stool, serum, or abscess fluid antigen
- Indirect hemagglutination (antibody)
- CT or ultrasound for suspected abscess
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
References
- ↑ Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.