Pediculosis capitis

Last reviewed: 28 Aug 2022
Last updated: 10 Mar 2022

Summary

Definition

History and exam

Key diagnostic factors

  • scalp pruritus
  • live nymphal or adult louse
  • eggs visible on hair shaft within 1 cm of scalp
More key diagnostic factors

Other diagnostic factors

  • small red papules under hairline at nape of neck
  • lymphadenopathy
  • erythema with honey-colored crust on scalp
Other diagnostic factors

Risk factors

  • 3 to 12 years of age
  • female sex
  • race
  • close contact with an infested individual
  • overcrowding or close living conditions
  • low socioeconomic status
  • poor hygiene
  • contact with contaminated clothes, hair care items, bedding
More risk factors

Diagnostic investigations

1st investigations to order

  • no tests required
More 1st investigations to order

Treatment algorithm

ACUTE

children <2 months of age

children ≥2 months and <2 years of age

children ≥2 years of age and adults

Contributors

Authors

Aicha Salhi, MD

Professor of Dermatology

Faculty of Medicine

University of Algiers

Algeria

Disclosures

AS declares that she has no competing interests.

Acknowledgements

Professor Aicha Salhi would like to gratefully acknowledge Professor Hermann Feldmeier and Professor Barbara L. Frankowski, previous contributors to this topic.

Disclosures

HF has received consultant and lecture fees from Pohl-Boskamp GmbH, and Co KG, Hohenlockstedt, Germany, and Almirall Hermal GmbH, Reinbek, Germany; both companies produce various anti-head louse compounds. He is also an author of several references cited in this topic. BLF is an author of a reference cited in this topic.

Peer reviewers

Richard J. Pollack, PhD

Research Associate

Laboratory of Public Health Entomology

Department of Immunology and Infectious Diseases

Harvard School of Public Health

Boston

MA

Disclosures

RJP has received a research donation by Taro Pharmaceuticals (manufacturer of Ovide) and has been compensated as an independent consultant for scientific review services by Topaz Pharmaceuticals, Hatchtech, and ParaPro, each developing products for the US market. RJP holds no financial interest in any of these companies or their products. RJP is an author of several references cited in this topic.

Ian F. Burgess, MSc, MPhil

Professor

Director

Medical Entomology Centre

University of Cambridge

Cambridge

UK

Disclosures

IFB has been a consultant to various manufacturers of pharmaceutical products, alternative therapies, and combs for treating louse infections. IFB is an author of a number of references cited in this topic.

Kosta Y. Mumcuoglu, PhD

Professor

Department of Parasitology

Hebrew University-Hadassah Medical School

Jerusalem

Israel

Disclosures

KYM is an author of several references cited in this topic.

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