Please read: Important 2013 cancer research update from Dr. Michael Camilleri

Free

E-newsletter

Subscribe to Housecall

Our weekly general interest
e-newsletter keeps you up to date on a wide variety of health topics.

Sign up now

Tests and diagnosis

By Mayo Clinic staff

During an examination, your doctor may examine you for lice using a magnifying lens and check for nits using a special light, called a Wood's light, which makes the nits look pale blue.

Head lice
A diagnosis of head lice can be made after a live young or adult louse in the hair or on the scalp is found, or after one or more nits is seen on hair shafts located within 1/4 inch (6.4 millimeters) of the scalp.

If you don't see any live lice or you see nits that are more than 1/4 inch away from the scalp, the infestation is no longer active and you don't need treatment.

Body lice
A diagnosis of body lice may be made if eggs or crawling lice are found in the seams of clothing or on bedding. It's possible to see a body louse on skin if it crawls there to feed.

Pubic lice
Pubic lice are diagnosed when moving lice or nits are seen on hair in the pubic area or on other areas of coarse hair, such as chest hair, eyebrows or eyelashes.

Treatments and drugs Preparing for your appointment
References
  1. Head lice: Frequently asked questions. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/head/gen_info/faqs.html. Accessed Feb. 14, 2012.
  2. Body lice: Frequently asked questions. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/body/gen_info/faqs.html. Accessed Feb. 14, 2012.
  3. Pubic "crab" lice: Frequently asked questions. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/pubic/gen_info/faqs.html. Accessed Feb. 14, 2012.
  4. Mandell GL, et al. Mandell, Douglas, and Bennett's Priciples and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa.: Churchill Livingstone Elsevier; 2010. http://www.mdconsult.com/book/player/linkTo?type=bookPage&isbn=978-0-443-06839-3&eid=4-u1.0-B978-0-443-06839-3..00293-9. Accessed Jan. 20, 2010.
  5. Goldstein AO, et al. Pediculosis capitis. http://www.uptodate.com/index. Accessed Feb. 16, 2012.
  6. Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/content.aspx?aID=2898131. Accessed Feb. 17, 2012.
  7. Burkhart CN, et al. Fomite transmission in head lice. Journal of the American Academy of Dermatology. 2007;56:1044.
  8. Head lice: Treatment. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/head/treatment.html. Accessed Feb. 14, 2012.
  9. Body lice: Treatment. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/body/treatment.html. Accessed Feb. 14, 2012.
  10. Pubic "crab" lice: Treatment. Centers for Disease Control and Prevention. http://www.cdc.gov/parasites/lice/pubic/treatment.html. Accessed Feb. 14, 2012.
  11. Mumcuoglu KY, et al. Repellency of citronella for head lice: Double-blind randomized trial of efficacy and safety. Israel Medical Association Journal. 2004;6:756.
  12. Semmler M, et al. Repellency against head lice (Pediculus humanus capitis). Parasitology Research. 2010;106:729.
  13. Frankowski BL, et al. Head lice. Pediatrics. 2010;126:392.
DS00368 May 22, 2012

© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "EmbodyHealth," "Enhance your life," and the triple-shield Mayo Clinic logo are trademarks of Mayo Foundation for Medical Education and Research.

  • Reprints
  • Print

  • Share on:

  • Email

Advertisement


Text Size: smaller largerlarger