epocrates logo
epocrates logo
epocrates logo
  • 0

Diseases

Pediculosis capitis

OVERVIEW

  • Highlights & Basics
  • Images

DIAGNOSIS

  • Diagnostic Approach
  • Risk Factors
  • History & Exam
  • Tests
  • Differential Diagnosis
  • Criteria
  • Screening

TREATMENT

  • Tx Approach
  • Tx Options
  • Emerging Tx
  • Prevention

FOLLOW-UP

  • Overview
  • Complications

REFERENCES

  • Citations
  • Guidelines
  • Credits

PATIENT RESOURCES

  • Patient Instructions

Highlights & Basics

AAFont SizeShareMore Information
Key Highlights
  • Head lice infestations (pediculosis capitis) are associated with little morbidity but can cause strain and distress to parents, caregivers, and teachers.

  • Effective pediculicides exist, but head lice in some areas have developed resistance to products with a neurotoxic mode of action.

  • Products with a physical mode of action are an alternative to neurotoxic treatments; they are nontoxic, and lice are less likely to develop resistance.

  • Physicians should take an active role in the treatment of head lice infestations by being available to confirm active cases and being knowledgeable about first- and second-line treatment options in their communities.

  • Knowledge of the life cycle of lice and the mode of transmission emphasize that "no nit" policies in schools are not effective and should be abandoned.

Adult louse seen under a microscope
Adult louse seen under a microscope
From the collection of Dr Richard Pollack; used with permission

Quick Reference

  • History & Exam

    • Key Factors

      • Other Factors

        More information...
      • Diagnostics Tests

          More information...
        • Treatment Options

            More information...

          Definition

          Epidemiology

          Etiology

          Pathophysiology

          content by BMJ Group
          Last updated

          Images

          • Adult louse seen under a microscope

            Adult louse seen under a microscope

          • Unhatched nit of a head louse

            Unhatched nit of a head louse

          • Nymph of head louse about to emerge from egg

            Nymph of head louse about to emerge from egg

          • Illustration of life cycle of head lice

            Illustration of life cycle of head lice

          • Empty louse egg cases (nits)

            Empty louse egg cases (nits)

          Citations

            Key Articles

            • American Academy of Pediatrics, Nolt D, Moore S, et al. Head Lice. Pediatrics. 2022 Oct 1;150(4):e2022059282.[Abstract][Full Text]

            • Cummings C, Finlay JC, MacDonald NE et al. Head lice infestations: a clinical update. Paediatr Child Health. 2024 Jan 11;23(1):e18-24.[Full Text]

            Referenced Articles

            • 1. Burgess IF, Silverston P. Head lice. Clin Evid (Online). January 2015 [internet publication].[Abstract][Full Text]

            • 2. Burgess I. Human lice and their control. Ann Rev Entomol. 2004 Jan;49:457-81.[Abstract]

            • 3. Ko CJ, Elston DM. Pediculosis. J Am Acad Dermatol. 2004 Jan;50(1):1-12.[Abstract]

            • 4. Leung AK, Fong JH, Pinto-Rojas A. Pediculosis capitis. J Ped Health Care. 2005 Nov-Dec;19(6):369-73.[Abstract]

            • 5. American Academy of Pediatrics, Nolt D, Moore S, et al. Head Lice. Pediatrics. 2022 Oct 1;150(4):e2022059282.[Abstract][Full Text]

            • 6. Downs A, Oxley J. Head lice infestations in different ethnic groups. Int J Derm. 2001 Mar;40(3):237-8.[Abstract]

            • 7. Falagas ME, Matthaiou DK, Rafailidis PI, et al. Worldwide prevalence of head lice. Emerg Infect Dis. 2008 Sep;14(9):1493-4.[Abstract][Full Text]

            • 8. Counahan M, Andrews R, Buttner P, et al. Head lice prevalence in primary schools in Victoria, Australia. J Paediatr Child Health. 2004 Nov;40(11):616-9.[Abstract]

            • 9. Harris J, Crawshaw JG, Millership S. Incidence and prevalence of head lice in a district health authority area. Commun Dis Public Health. 2003 Sep;6(3):246-9.[Abstract]

            • 10. Fan CK, Liao CW, Wu MS, et al. Prevalence of pediculus capitis infestation among school children of Chinese refugees residing in mountainous areas of northern Thailand. Kaohsiung J Med Sci. 2004 Apr;20(4):183-7.[Abstract]

            • 11. Farjallah D, Belgacem S, Remadi L, et al. Prevalence of pediculosis among primary school children in Tunisia. East Mediterr Health J. 2024 Sep 1;30(8):561-9.[Abstract][Full Text]

            • 12. Lesshafft H, Baier A, Guerra H, et al. Prevalence and risk factors associated with pediculosis capitis in an impoverished urban community in lima, peru. J Glob Infect Dis. 2013 Oct;5(4):138-43.[Abstract][Full Text]

            • 13. Meinking TL. Infestations: pediculosis. Curr Probl Dermatol. 1996;24:157-63.[Abstract]

            • 14. Estrada JS, Morris RI. Pediculosis in a school population. J Sch Nurs. 2000 Aug;16(3):32-8.[Abstract]

            • 15. Gratz NG; World Health Organization/WHOPES. Human lice: their prevalence, control and resistance to insecticides - a review, 1985-1997. August 1997 [internet publication].[Full Text]

            • 16. Houhamdi L, Parola P, Raoult D. Les poux et les maladies transmises à l'homme [in French]. Médecine Tropicale. 2005;65:13-23.

            • 17. Feldmeier H. Lice as vectors of pathogenic microorganisms. In: Heukelbach J, ed. Management and control of head lice infestation. Bremen: UNIMED; 2010:132-5.

            • 18. Boutellis A, Mediannikov O, Bilcha KD, et al. Borrelia recurrentis in head lice, Ethiopia. Emerg Infect Dis. 2013 May;19(5):796-8.[Abstract][Full Text]

            • 19. Antinori S, Mediannikov O, Corbellino M, et al. Louse-borne relapsing fever among East African refugees in Europe. Travel Med Infect Dis. 2016 Mar-Apr;14(2):110-4.[Abstract]

            • 20. Speare R, Thomas G, Cahill C. Head lice are not found on floors in primary school classrooms. Aus N Z J Pub Health. 2002;26(3):208-11.[Abstract]

            • 21. Heukelbach J, Wilcke T, Winter B, et al. Epidemiology and morbidity of scabies and pediculosis capitis in resource-poor communities in Brazil. Br J Derm. 2005 Jul;153(1):150-6.[Abstract]

            • 22. Willems S, Lapeere H, Haedens N, et al. The importance of socio-economic status and individual characteristics on the prevalence of head lice in schoolchildren. Eur J Dermatol. 2005 Sep-Oct;15(5):387-92.[Abstract]

            • 23. Chunge RN, Scott FE, Underwood JE, et al. A pilot study to investigate transmission of head lice. Can J Public Health. 1991 May-Jun;82(3):207-8.[Abstract]

            • 24. Maunder JW. Human lice: some basic facts and misconceptions. Bull Pan Am Health Organ. 1985;19(2):194-7.[Abstract]

            • 25. Burkhart CN. Fomite transmission with head lice: a continuing controversy. Lancet. 2003 Jan 11;361(9352):99-100.[Abstract]

            • 26. Burkhart CN, Burkhart CG. Fomite transmission in head lice. J Am Acad Derm. 2007 Jun;56(6):1044-7.[Abstract]

            • 27. Speare R, Cahill C, Thomas G. Head lice on pillows, and strategies to make a small risk even less. Int J Derm. 2003 Aug;42(8):626-9.[Abstract]

            • 28. Williams LK, Reichert A, MacKenzie WR, et al. Lice, nits, and school policy. Pediatrics. 2001 May;107(5):1011-5.[Abstract]

            • 29. Mumcuoglu KY, Meinking TA, Burkhart CN, et al. Head louse infestations: the "no nit" policy and its consequences. Int J Derm. 2006 Aug;45(8):891-6.[Abstract]

            • 30. Public Health Medicine Environmental Group. Head lice: evidence-based guidelines based on the Stafford Report - 2012 update [internet publication].[Full Text]

            • 31. Mumcuoglu KY, Friger M, Ioffe-Uspensky I, et al. Louse comb versus direct visual examination for the diagnosis of head louse infestations. Ped Derm. 2001 Jan-Feb;18(1):9-12.[Abstract]

            • 32. Burgess I. Detection combing. Nurs Times. 2002 Nov 12-18;98(46):57.[Abstract]

            • 33. Pollack RJ, Kiszewski AD, Spielman A. Overdiagnosis and consequent mismanagement of head louse infestation in North America. Pediatr Infect Dis J. 2000 Aug;19(8):689-93.[Abstract]

            • 34. Jahnke C, Bauer E, Hengge UR, et al. Accuracy of diagnosis of pediculosis capitis: visual inspection vs wet combing. Arch Dermatol. 2009 Mar;145(3):309-13.[Abstract][Full Text]

            • 35. Balcioglu C, Burgess IF, Limoncu ME, et al. Plastic detection comb better than visual screening for diagnosis of head louse infestation. Epidemiol Infect. 2008 Oct;136(10):1425-31.[Abstract]

            • 36. Hootman J. Quality improvement projects related to pediculosis management. J School Nursing. 2002 Apr;18(2):80-6.[Abstract]

            • 37. Feldmeier H. Pediculosis capitis: new insights into epidemiology, diagnosis and treatment. Eur J Clin Microbiol Infect Dis. 2012 Sep;31(9):2105-10.[Abstract]

            • 38. Pollack RJ. The role of the school in battling head lice. Our children (US National PTA). 2007 [internet publication].[Full Text]

            • 39. Cummings C, Finlay JC, MacDonald NE et al. Head lice infestations: a clinical update. Paediatr Child Health. 2024 Jan 11;23(1):e18-24.[Full Text]

            • 40. Jones KN, English JC. Review of common therapeutic options in the United States for the treatment of Pediculosis capitis. Clin Inf Dis. 2003 Jun 1;36(11):1355-61.[Abstract]

            • 41. Downs AM. Managing head lice in an era of increasing resistance to insecticides. Am J Clin Derm. 2004;5(3):169-77.[Abstract]

            • 42. Meinking TL, Entzel P, Villar ME, et al. Comparative efficacy of treatments for Pediculosis capitis infestations. Arch Dermatol. 2001 Mar;137(3):287-92.[Abstract][Full Text]

            • 43. Burkhart CG, Burkhart CN. Safety and efficacy of pedulicides for head lice. Expert Opin Drug Saf. 2006 Jan;5(1):169-79.[Abstract]

            • 44. Burkhart CG, Burkhart CN. Head lice therapies revisited. Derm Online J. 2006 Oct 31;12(6):3.[Abstract]

            • 45. Burkhart CG. Relationship of treatment-resistant head lice to the safety and efficacy of pediculicides. Mayo Clin Proc. 2004 May;79(5):661-6.[Abstract]

            • 46. Lebwohl M, Clark L, Levitt J. Therapy for head lice based on life cycle, resistance, and safety considerations. Pediatrics. 2007 May;119(5):965-74.[Abstract]

            • 47. Do-Pham G, Le Cleach L, Giraudeau B, et al. Designing randomized-controlled trials to improve head-louse treatment: systematic review using a vignette-based method. J Invest Dermatol. 2014 Mar;134(3):628-34.[Abstract]

            • 48. Centers for Disease Control and Prevention. Parasites: lice: head lice treatment. August 2019 [internet publication].[Full Text]

            • 49. Kristensen M, Knorr M, Rasmussen AM, et al. Survey of permethrin and malathion resistance in human head lice populations from Denmark. J Med Entomol. 2006 May;43(3):533-8.[Abstract][Full Text]

            • 50. Kasai S1, Ishii N, Natsuaki M, Fukutomi H, et al. Prevalence of kdr-like mutations associated with pyrethroid resistance in human head louse populations in Japan. J Med Entomol. 2009 Jan;46(1):77-82.[Abstract][Full Text]

            • 51. Hunter JA, Barker SC. Susceptibility of head lice (Pediculus humanus capitis) to pediculicides in Australia. Parasitol Res. 2003 Aug;90(6):476-8.[Abstract]

            • 52. Durand R, Millard B, Bouges-Michel C, et al. Detection of pyrethroid resistance gene in head lice in schoolchildren from Bobigny, France. J Med Entomol. 2007 Sep;44(5):796-8.[Abstract][Full Text]

            • 53. Bailey AM, Prociv P. Persistent head lice following multiple treatments: evidence for insecticide resistance in Pediculus humanus capitis. Australas J Dermatol. 2000 Nov;41(4):250-4.[Abstract]

            • 54. Sendzik J, Stahlmann R. Arzneimittel gegen Kopflausbefall. Toxikologie und Wirksamkeit [in German]. Med Monatsschr Pharm. 2005 May;28(5):167-72.

            • 55. Menegaux F, Baruchel A, Bertrand Y, et al. Household exposure to pesticides and risk of childhood acute leukaemia. Occup Environ Med. 2006 Feb;63(2):131-4.[Abstract][Full Text]

            • 56. US Food and Drug Administration. FDA public health advisory: safety of topical lindane products for the treatment of scabies and lice. 2009 [internet publication].[Full Text]

            • 57. Takano-Lee M, Edman JD, Mullens BA, et al. Home remedies to control head lice: assessment of home remedies to control the human head louse, Pediculus humanus capitis. J Ped Nursing. 2004 Dec;19(6):393-8.[Abstract]

            • 58. Priestley CM, Burgess IF, Williamson EM. Lethality of essential oil constituents towards the human louse, Pediculus humanus, and its eggs. Fitoterapia. 2006 Jun;77(4):303-9.[Abstract]

            • 59. Speare R, Canyon DV, Cahill C, et al. Comparative efficacy of two nit combs in removing head lice (Pediculosis capitis) and their eggs. Int J Dermatol. 2007 Dec;46(12):1275-8.[Abstract]

            • 60. Lapeere H, Brochez L, Verhaeghe E, et al. Efficacy of products to remove eggs of Pediculus humanus capitis (Phthiraptera: Pediculidae) from the human hair. J Med Entomol. 2014 Mar;51(2):400-7.[Abstract][Full Text]

            • 61. Bainbridge CV, Klein GL, Neibart SI, et al. Comparative study of the clinical effectiveness of a pyrethrin-based pediculicide with combing versus a permethrin-based pediculicide with combing. Clin Pediatr (Phila). 1998 Jan;37(1):17-22.[Abstract]

            • 62. Plastow L, Luthra M, Wright J, et al. Head lice infestation: bug busting vs traditional treatment. J Clin Nursing. 2001 Nov;10(6):775-83.[Abstract]

            • 63. Tebruegge M, Runnacles J. Is wet combing effective in children with pediculosis capitis infestation? Arch Dis Child. 2007 Sep;92(9):818-20.[Abstract]

            • 64. Monheit BM, Norris MM. Is combing the answer to head lice? J Sch Health. 1986 Apr;56(4):158-9.[Abstract]

            • 65. O'Brien E. Detection and removal of head lice with an electronic comb: zapping the louse! J Pediatr Nurs. 1998 Aug;13(4):265-6.[Abstract]

            • 66. Burkhart CN, Burkhart CG, Pchalek I, et al. The adherent cylindrical nit structure and its chemical denaturation in vitro: an assessment with therapeutic implications for head lice. Adolesc Med. 1998 Jul;152(7):711-2.[Abstract]

            • 67. DeFelice J, Rumsfield J, Bernstein JE, et al. Clinical evaluation of an after-pediculicide nit removal system. Int J Dermatol. 1989 Sep;28(7):468-70.[Abstract]

            • 68. Goates BM, Atkin JS, Wilding KG, et al. An effective nonchemical treatment for head lice: a lot of hot air. Pediatrics. 2006 Nov;118(5):1962-70.[Abstract]

            • 69. Pearlman DL. A simple treatment for head lice: dry-on, suffocation-based pediculicide. Pediatrics. 2004 Sep;114(3):e275-9.[Abstract][Full Text]

            • 70. Pearlman D. Cetaphil cleanser (Nuvo Lotion) cures head lice. Pediatrics. 2005 Dec;116(6):1612.[Abstract]

            • 71. Tomalik-Scharte D, Lazar A, Meins J, et al. Dermal absorption of permethrin following topical administration. Eur J Clin Pharmacol. 2005 Jul;61(5-6):399-404.[Abstract]

            • 72. Gao JR, Yoon KS, Lee SH, et al. Increased frequency of the T929I and L932F mutations associated with knockdown resistance in permethrin-resistant populations of the human head louse, Pediculus capitis, from California, Florida, and Texas. Pestic Biochem Physiol. 2003 Nov;77:115-24.[Full Text]

            • 73. Meinking TL, Vicaria M, Eyerdam DH, et al. A randomized, investigator-blinded, time-ranging study of the comparative efficacy of 0.5% malathion gel versus Ovide Lotion (0.5% malathion) or Nix Creme Rinse (1% permethrin) used as labeled, for the treatment of head lice. Ped Derm. 2007 Jul-Aug;24(4):405-11.[Abstract]

            • 74. Meinking TL, Vicaria M, Eyerdam DH, et al. Efficacy of a reduced application time of Ovide lotion (0.5% malathion) compared to Nix creme rinse (1% permethrin) for the treatment of head lice. Ped Derm. 2004 Nov-Dec;21(6):670-4.[Abstract]

            • 75. Yoon KS, Gao JR, Lee SH, et al. Permethrin-resistant human head lice, Pediculus capitis, and their treatment. Arch Dermatol. 2003 Aug;139(8):994-1000.[Abstract][Full Text]

            • 76. Meinking TL, Serrano L, Hard B, et al. Comparative in vitro pediculicidal efficacy of treatments in a resistant head lice population in the United States. Arch Dermatol. 2002 Feb;138(2):220-4.[Abstract][Full Text]

            • 77. Abramowicz M, ed. Drugs for head lice. Med Lett Drugs Ther. 1997 Jan 17;39(992):6-7.[Abstract]

            • 78. Pollack RJ, Kiszewski A, Armstrong P, et al. Differential permethrin susceptibility of head lice sampled in the United States and Borneo. Arch Pediatr Adolesc Med. 1999 Sep;153(9):969-73.[Abstract]

            • 79. Burgess IF, Lee PN, Brown CM. Randomised, controlled, parallel group clinical trials to evaluate the efficacy of isopropyl myristate/cyclomethicone solution against head lice. Pharm J. 2008;280:371-5.

            • 80. Kaul N, Palma KG, Silagy SS, et al. North American efficacy and safety of a novel pediculicide rinse, isopropyl myristate 50% (Resultz). J Cutan Med Surg. 2007 Sep-Oct;11(5):161-7.[Abstract]

            • 81. Chosidow O, Giraudeau B, Cottrell J, et al. Oral ivermectin versus malathion lotion for difficult-to-treat head lice. New Engl J Med. 2010 Mar 11;362(10):896-905.[Abstract]

            • 82. POEMs Research Summaries. Ivermectin safe and effective for treatment of resistant head lice. J Natl Med Assoc. 2010;102:662-3.

            • 83. Karacic I, Yawalker SJ. A single application of crotamiton lotion in the treatment of patients with pediculosis capitis. Int J Dermatol. 1982 Dec;21(10):611-3.[Abstract]

            • 84. Heukelbach J, Oliveira FA, Richter J, et al. Dimeticone-based pediculicides: a physical approach to eradicate head lice. Open Dermatol J. 2010;4:77-81.[Full Text]

            • 85. Richling I, Böckeler W. Lethal effects of treatment with a special dimeticone formula on head lice and house crickets (Orthoptera, Ensifera: Acheta domestica and Anoplura, phthiraptera: Pediculus humanus). Insights into physical mechanisms. Arzneimittelforschung. 2008;58(5):248-54.[Abstract]

            • 86. Burgess IF. The mode of action of dimeticone 4% lotion against head lice, Pediculus capitis. BMC Pharmacol. 2009 Feb 20;9:3.[Abstract][Full Text]

            • 87. Kurt O, Balcioğlu IC, Burgess IF, et al. Treatment of head lice with dimeticone 4% lotion: comparison of two formulations in a randomised controlled trial in rural Turkey. BMC Public Health. 2009 Dec 1;9:441.[Abstract][Full Text]

            • 88. Burgess IF, Brunton ER, Burgess NA. Single application of 4% dimeticone liquid gel versus two applications of 1% permethrin creme rinse for treatment of head louse infestation: a randomised controlled trial. BMC Dermatol. 2013 Apr 1;13:5.[Abstract][Full Text]

            • 89. Burgess IF, Brown CM, Lee PN. Treatment of head louse infestation with 4% dimeticone lotion: randomised controlled equivalence trial. BMJ. 2005 Jun 18;330(7505):1423.[Abstract][Full Text]

            • 90. Heukelbach J, Pilger D, Oliveira FA, et al. A highly efficacious pediculicide based on dimeticone: randomized observer blinded comparative trial. BMC Infect Dis. 2008;8:115.[Abstract][Full Text]

            • 91. Burgess IF1, Lee PN, Matlock G. Randomised, controlled, assessor blind trial comparing 4% dimeticone lotion with 0.5% malathion liquid for head louse infestation. PLoS One. 2007 Nov 7;2(11):e1127.[Abstract][Full Text]

            • 92. Strycharz JP, Yoon KS, Clark JM. A new ivermectin formulation topically kills permethrin-resistant human head lice (Anoplura: Pediculidae). J Med Entomol. 2008 Jan;45(1):75-81.[Abstract][Full Text]

            • 93. Heukelbach J, Sonnberg S, Becher H, et al. Ovicidal efficacy of high concentration dimeticone: a new era of head lice treatment. J Am Acad Dermatol. 2011 Apr;64(4):e61-2.[Abstract]

            • 94. Burgess IF, Burgess NA. Dimeticone 4% liquid gel found to kill all lice and eggs with a single 15 minute application. BMC Res Notes. 2011 Jan 25;4:15.[Abstract][Full Text]

            • 95. Feldmeier H. Treatment of pediculosis capitis: a critical appraisal of the current literature. Am J Clin Dermatol. 2014 Oct;15(5):401-12.[Abstract]

            • 96. Burgess IF, Lee PN, Kay K, et al. 1,2-Octanediol, a novel surfactant, for treating head louse infestation: identification of activity, formulation, and randomised, controlled trials. PLoS One. 2012;7(4):e35419.[Abstract][Full Text]

            • 97. Burgess IF, Burgess NA, Brunton ER. Tocopheryl acetate 20% spray for elimination of head louse infestation: a randomised controlled trial comparing with 1% permethrin creme rinse. BMC Pharmacol Toxicol. 2013 Sep 3;14:43.[Abstract][Full Text]

            • 98. National Health and Medical Research Council (Australia). Staying healthy: preventing infectious diseases in early childhood education and care services, fifth edition. June 2013 [internet publication].[Full Text]

            • 99. National Association of School Nurses (US). Head lice management in the school setting: position statement. January 2016 [internet publication].[Full Text]

          Have feedback?
          Tell us about your experience
          Scroll to Top
          epocrates logo

          Sign in to access our clinical decision support tools

          Sign inCreate Account
          Download Epocrates from the App StoreDownload Epocrates from the Play Store
          About UsFeaturesBusiness SolutionsHelp & Feedback
          © 2026 epocrates, Inc.   Terms of UsePrivacy PolicyEditorial PolicyDo Not Sell or Share My Information