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
Other diagnostic factors
- small red papules under hairline at nape of neck
- lymphadenopathy
- erythema with honey-colored crust on scalp
Risk factors
- 3 to 12 years of age
- female sex
- close contact with an infested individual
- overcrowding or close living conditions
- low socioeconomic status
- poor hygiene
- contact with contaminated clothes, hair care items, bedding
Diagnostic tests
1st tests to order
- no tests required
Treatment algorithm
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.
Differentials
- Seborrheic dermatitis
- Other objects in hair
More DifferentialsGuidelines
- Clinical report: head lice
- Parasites: lice: head lice treatment
More GuidelinesPatient information
Head lice
More Patient information
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