Last reviewed: February 2018
Last updated: August  2017



History and exam

Key diagnostic factors

  • travel to, or immigration from, endemic areas with poor sanitation, hygiene, and agricultural practices

Other diagnostic factors

  • asymptomatic
  • co-infection with other parasites
  • developmental delay
  • malnutrition
  • fever
  • cough
  • wheezing
  • dyspnea
  • hemoptysis
  • hypoxia
  • tachypnea
  • rhonchi, rales
  • retractions
  • urticarial skin lesions
  • abdominal pain
  • anorexia
  • dyspepsia
  • nausea
  • vomiting
  • diarrhea
  • constipation
  • abdominal distension
  • reduced or absent bowel sounds
  • hypotension
  • RUQ tenderness
  • hepatomegaly
  • jaundice
  • signs/symptoms of iron deficiency anemia or kwashiorkor

Risk factors

  • children <14 years
  • poverty
  • poor sanitation
  • poor hygiene
  • history of travel to or residence in endemic areas
  • warm climate

Diagnostic investigations

1st investigations to order

  • stool microscopy
  • CXR
  • abdominal x-ray
Full details

Investigations to consider

  • gastrografin contrast study
  • sputum/gastric aspirate microscopy
  • CBC
  • barium follow-through
  • abdominal ultrasound
  • abdominal CT
  • ERCP
Full details

Emerging tests

  • antibodies to Ascaris lumbricoides
  • serum IgE
  • interleukin (IL)-4, IL-5, and IL-13
  • urine-based gas liquid chromatography
Full details

Treatment algorithm


Authors VIEW ALL

Professor of Pediatrics, Microbial Pathogenesis, and Public Health


Yale World Fellows Program

New Haven



MC declares that he has no competing interests.

Dr Michael Cappello would like to gratefully acknowledge Dr Samantha H. Johnston and Dr Claire Panosian, previous contributors to this monograph. SHJ owns a share in a company (Merck & Co., Inc.) that produces ivermectin, an alternative therapy for ascariasis. CP declares that she has no competing interests.

Peer reviewers VIEW ALL


Stanford Health Promotion Network

Stanford School of Medicine

Palo Alto



YM declares that he has no competing interests.

Associate Professor

Department of Medical Parasitology and Mycology

School of Public Health

Tehran University of Medical Sciences



MBR declares that he has no competing interests.

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