Pinworms in Emergency Medicine

Author: Joseph J Bocka, MD; Chief Editor: Pamela L Dyne, MD more...

Updated: Apr 28, 2011

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Background
Pathophysiology
Epidemiology
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Background

Enterobius vermicularis (pinworm) is the most common intestinal parasite in the United States. Despite primarily living in the gut, the most common chief complaint is anal itching (pruritus). Most patients with pinworm infestation, however, are asymptomatic.

Pinworms in a young patient.

Pathophysiology

E vermicularis lives in the small intestines, primarily the ileocecal region. The gravid female migrates to the anus and deposits eggs in the perianal skin folds, usually at nighttime. The movement of the female and the ova cause intense local itching. Ova may survive for up to 3 weeks before hatching. The hatched larvae can then migrate back into the anus and lower intestine, causing retroinfection. Embryonated eggs may be released into the air or onto fomites (eg, bedding, clothing, toys, paper money) or onto hands and then placed directly into the mouth and swallowed (autoinfection), after which they settle in the small intestines.

Frequency

United States

E vermicularis is the most common helminth in the United States. General prevalence in children is reported to be 0.2-20%. Prevalence in institutionalized persons is reported to be 50-100%.

International

A similar prevalence of pinworm infestation has been reported in European countries.

Mortality/Morbidity

Pinworm infestation is very rarely fatal; death and morbidity are from secondary infection. A 28-68% increased risk for appendicitis is associated with pinworm infestation.^[1]

Sex

Overall, males are affected twice as often as females are except in people aged 5-14 years, when females predominate.

Age

School-aged children have the highest prevalence of pinworm infestation.

Proceed to Clinical Presentation

Contributor Information and Disclosures

Author

Joseph J Bocka, MD Director of Shelby Emergency Department, Attending Emergency Physician at Mansfield Hospital, Med Central Health System (Mansfield and Shelby, Ohio); Emergency Medical Service Medical Director for several services

Joseph J Bocka, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, National Association of EMS Physicians, and Phi Beta Kappa

Disclosure: Nothing to disclose.

Specialty Editor Board

David A Peak, MD Assistant Residency Director of Harvard Affiliated Emergency Medicine Residency, Attending Physician, Massachusetts General Hospital; Consulting Staff, Department of Hyperbaric Medicine, Massachusetts Eye and Ear Infirmary

David A Peak, MD is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, Society for Academic Emergency Medicine, and Undersea and Hyperbaric Medical Society

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Senior Pharmacy Editor, eMedicine

Disclosure: eMedicine Salary Employment

Jeter (Jay) Pritchard Taylor III, MD Compliance Officer, Attending Physician, Emergency Medicine Residency, Department of Emergency Medicine, Palmetto Health Richland, University of South Carolina School of Medicine; Medical Director, Department of Emergency Medicine, Palmetto Health Baptist

Jeter (Jay) Pritchard Taylor III, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

John D Halamka, MD, MS Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center

John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Pamela L Dyne, MD Professor of Clinical Medicine/Emergency Medicine, University of California, Los Angeles, David Geffen School of Medicine; Attending Physician, Department of Emergency Medicine, Olive View-UCLA Medical Center

Pamela L Dyne, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

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