- Adam O Goldstein, MD, MPH
Adam O Goldstein, MD, MPH
- Department of Family Medicine
- University of North Carolina at Chapel Hill
- Beth G Goldstein, MD
Beth G Goldstein, MD
- Adjunct Clinical Assistant Professor
- Department of Dermatology
- University of North Carolina at Chapel Hill
- Section Editors
- Robert P Dellavalle, MD, PhD, MSPH
Robert P Dellavalle, MD, PhD, MSPH
- Section Editor — Dermatology
- Associate Professor of Dermatology and Public Health
- Denver VA Medical Center, University of Colorado School of Medicine and Colorado School of Public Health
- Moise L Levy, MD
Moise L Levy, MD
- Section Editor — Pediatric Dermatology
- Clinical Professor of Dermatology and Pediatrics
- Baylor College of Medicine
- Professor of Medicine
- Dell Medical School/University of Texas, Austin
- Ted Rosen, MD
Ted Rosen, MD
- Section Editor — Infections and Infestations
- Professor, Department of Dermatology
- Baylor College of Medicine
Pediculosis capitis is a common condition caused by infestation of the hair and scalp by Pediculus humanus capitis (the head louse), one of three distinct varieties of lice specifically parasitic for humans (figure 1) . The clinical manifestations, diagnosis, and treatment of pediculosis capitis will be reviewed here. Other forms of louse infestation, including pediculosis corporis and pediculosis pubis, are discussed separately. (See "Pediculosis corporis" and "Pediculosis pubis and pediculosis ciliaris".)
Pediculosis capitis occurs worldwide and in individuals of all socioeconomic backgrounds . Children are affected most frequently.
Males appear to be less susceptible to lice infestations than females [3-5], and in the United States, black children are affected much less frequently than white children and others . The reasons for these findings are uncertain. Studies investigating the impact of long hair length on the risk for infestation have yielded conflicting results [3,4,7]. The lower incidence in black children in the US may be related to a low prevalence of lice that are capable of grasping the shape or width of certain types of hair .
The life span of the female louse is about one month, during which she lays 7 to 10 eggs per day, cementing them firmly to the base of a host hair. The eggs, commonly called "nits," are oval capsules that hatch in eight days, releasing nymphs that require another eight days to mature (picture 1A-B). After hatching, egg cases become white and more visible.
Adult head lice are gray-white, 2 to 3 mm in length (picture 2A-B), and equipped with mouth parts adapted to sucking blood and legs adapted to grasping hairs. Adults feed both on the scalp and adjacent areas of the face and neck. Adult lice can survive up to 55 hours without a host , but probably dehydrate and become nonviable long before their death .
- Ko CJ, Elston DM. Pediculosis. J Am Acad Dermatol 2004; 50:1.
- Roberts RJ. Clinical practice. Head lice. N Engl J Med 2002; 346:1645.
- Counahan M, Andrews R, Büttner P, et al. Head lice prevalence in primary schools in Victoria, Australia. J Paediatr Child Health 2004; 40:616.
- Suleman M, Fatima T. Epidemiology of head lice infestation in school children at Peshawar, Pakistan. J Trop Med Hyg 1988; 91:323.
- Downs AM, Stafford KA, Coles GC. Head lice: prevalence in schoolchildren and insecticide resistance. Parasitol Today 1999; 15:1.
- http://www.cdc.gov/parasites/lice/head/index.html (Accessed on October 14, 2015).
- 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; 15:387.
- Chunge RN, Scott FE, Underwood JE, Zavarella KJ. A pilot study to investigate transmission of headlice. Can J Public Health 1991; 82:207.
- Frankowski BL, Bocchini JA Jr, Council on School Health and Committee on Infectious Diseases. Head lice. Pediatrics 2010; 126:392.
- Burkhart CN, Burkhart CG. Fomite transmission in head lice. J Am Acad Dermatol 2007; 56:1044.
- Canyon DV, Speare R. Indirect transmission of head lice via inanimate objects. Open Dermatology Journal 2010; 4:72.
- Takano-Lee M, Edman JD, Mullens BA, Clark JM. Transmission potential of the human head louse, Pediculus capitis (Anoplura: Pediculidae). Int J Dermatol 2005; 44:811.
- Speare R, Cahill C, Thomas G. Head lice on pillows, and strategies to make a small risk even less. Int J Dermatol 2003; 42:626.
- Speare R, Buettner PG. Hard data needed on head lice transmission. Int J Dermatol 2000; 39:877.
- Speare R, Thomas G, Cahill C. Head lice are not found on floors in primary school classrooms. Aust N Z J Public Health 2002; 26:208.
- Devore CD, Schutze GE, Council on School Health and Committee on Infectious Diseases, American Academy of Pediatrics. Head lice. Pediatrics 2015; 135:e1355.
- Jahnke C, Bauer E, Hengge UR, Feldmeier H. Accuracy of diagnosis of pediculosis capitis: visual inspection vs wet combing. Arch Dermatol 2009; 145:309.
- Mumcuoglu KY, Friger M, Ioffe-Uspensky I, et al. Louse comb versus direct visual examination for the diagnosis of head louse infestations. Pediatr Dermatol 2001; 18:9.
- http://www.cdc.gov/parasites/lice/head/diagnosis.html (Accessed on October 12, 2015).
- Williams LK, Reichert A, MacKenzie WR, et al. Lice, nits, and school policy. Pediatrics 2001; 107:1011.
- Keipert JA. Hair casts. Review and suggestion regarding nomenclature. Arch Dermatol 1986; 122:927.
- França K, Villa RT, Silva IR, et al. Hair casts or pseudonits. Int J Trichology 2011; 3:121.
- Bonifaz A, Gómez-Daza F, Paredes V, Ponce RM. Tinea versicolor, tinea nigra, white piedra, and black piedra. Clin Dermatol 2010; 28:140.
- Lebwohl M, Clark L, Levitt J. Therapy for head lice based on life cycle, resistance, and safety considerations. Pediatrics 2007; 119:965.
- Frankowski BL, Weiner LB, Committee on School Health the Committee on Infectious Diseases. American Academy of Pediatrics. Head lice. Pediatrics 2002; 110:638.
- 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; 138:220.
- Yoon KS, Gao JR, Lee SH, et al. Permethrin-resistant human head lice, Pediculus capitis, and their treatment. Arch Dermatol 2003; 139:994.
- Hunter JA, Barker SC. Susceptibility of head lice (Pediculus humanus capitis) to pediculicides in Australia. Parasitol Res 2003; 90:476.
- Kasai S, Ishii N, Natsuaki M, et al. Prevalence of kdr-like mutations associated with pyrethroid resistance in human head louse populations in Japan. J Med Entomol 2009; 46:77.
- 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; 44:796.
- Downs AM, Stafford KA, Hunt LP, et al. Widespread insecticide resistance in head lice to the over-the-counter pediculocides in England, and the emergence of carbaryl resistance. Br J Dermatol 2002; 146:88.
- 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; 153:969.
- Soderlund DM. Pyrethroids, knockdown resistance and sodium channels. Pest Manag Sci 2008; 64:610.
- Bialek R, Zelck UE, Fölster-Holst R. Permethrin treatment of head lice with knockdown resistance-like gene. N Engl J Med 2011; 364:386.
- Downs AM, Narayan S, Stafford KA, Coles GC. Effectiveness of ovide against malathion-resistant head lice. Arch Dermatol 2005; 141:1318.
- Spinosad (Natroba) topical suspension for head lice. Med Lett Drugs Ther 2011; 53:50.
- Ivermectin (Sklice) topical lotion for head lice. Med Lett Drugs Ther 2012; 54:61.
- Meinking TL, Clineschmidt CM, Chen C, et al. An observer-blinded study of 1% permethrin creme rinse with and without adjunctive combing in patients with head lice. J Pediatr 2002; 141:665.
- Malathion for treatment of head lice. Med Lett Drugs Ther 1999; 41:73.
- Frankowski BL. American Academy of Pediatrics guidelines for the prevention and treatment of head lice infestation. Am J Manag Care 2004; 10:S269.
- Takano-Lee M, Edman JD, Mullens BA, Clark JM. Home remedies to control head lice: assessment of home remedies to control the human head louse, Pediculus humanus capitis (Anoplura: Pediculidae). J Pediatr Nurs 2004; 19:393.
- 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. Pediatr Dermatol 2004; 21:670.
- 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 Crème Rinse (1% permethrin) used as labeled, for the treatment of head lice. Pediatr Dermatol 2007; 24:405.
- US FDA drug label. www.accessdata.fda.gov/drugsatfda_docs/label/2009/022129lbl.pdf (Accessed on March 25, 2010).
- Meinking TL, Villar ME, Vicaria M, et al. The clinical trials supporting benzyl alcohol lotion 5% (Ulesfia): a safe and effective topical treatment for head lice (pediculosis humanus capitis). Pediatr Dermatol 2010; 27:19.
- McCormack PL. Spinosad: in pediculosis capitis. Am J Clin Dermatol 2011; 12:349.
- Stough D, Shellabarger S, Quiring J, Gabrielsen AA Jr. Efficacy and safety of spinosad and permethrin creme rinses for pediculosis capitis (head lice). Pediatrics 2009; 124:e389.
- Pariser DM, Meinking TL, Bell M, Ryan WG. Topical 0.5% ivermectin lotion for treatment of head lice. N Engl J Med 2012; 367:1687.
- Roberts RJ, Casey D, Morgan DA, Petrovic M. Comparison of wet combing with malathion for treatment of head lice in the UK: a pragmatic randomised controlled trial. Lancet 2000; 356:540.
- Hill N, Moor G, Cameron MM, et al. Single blind, randomised, comparative study of the Bug Buster kit and over the counter pediculicide treatments against head lice in the United Kingdom. BMJ 2005; 331:384.
- Dawes M. Combing and combating head lice. BMJ 2005; 331:362.
- 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; 51:400.
- Chosidow O, Giraudeau B, Cottrell J, et al. Oral ivermectin versus malathion lotion for difficult-to-treat head lice. N Engl J Med 2010; 362:896.
- Ameen M, Arenas R, Villanueva-Reyes J, et al. Oral ivermectin for treatment of pediculosis capitis. Pediatr Infect Dis J 2010; 29:991.
- Currie MJ, Reynolds GJ, Glasgow NJ, Bowden FJ. A pilot study of the use of oral ivermectin to treat head lice in primary school students in Australia. Pediatr Dermatol 2010; 27:595.
- Pilger D, Heukelbach J, Khakban A, et al. Household-wide ivermectin treatment for head lice in an impoverished community: randomized observer-blinded controlled trial. Bull World Health Organ 2010; 88:90.
- Glaziou P, Nyguyen LN, Moulia-Pelat JP, et al. Efficacy of ivermectin for the treatment of head lice (Pediculosis capitis). Trop Med Parasitol 1994; 45:253.
- Burkhart CG, Burkhart CN. Head lice therapies revisited. Dermatol Online J 2006; 12:3.
- Nofal A. Oral ivermectin for head lice: a comparison with 0.5 % topical malathion lotion. J Dtsch Dermatol Ges 2010; 8:985.
- Twum-Danso NA. Serious adverse events following treatment with ivermectin for onchocerciasis control: a review of reported cases. Filaria J 2003; 2 Suppl 1:S3.
- Gardon J, Gardon-Wendel N, Kamgno J, et al. Serious reactions after mass treatment of onchocerciasis with ivermectin in an area endemic for Loa loa infection. Lancet 1997; 350:18.
- Burgess IF, Brown CM, Lee PN. Treatment of head louse infestation with 4% dimeticone lotion: randomised controlled equivalence trial. BMJ 2005; 330:1423.
- 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; 13:5.
- Burgess IF, 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; 2:e1127.
- 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.
- Ihde ES, Boscamp JR, Loh JM, Rosen L. Safety and efficacy of a 100% dimethicone pediculocide in school-age children. BMC Pediatr 2015; 15:70.
- US Food and Drug Administration public health advisory on lindane. www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm110845.htm (Accessed on October 09, 2009).
- Humphreys EH, Janssen S, Heil A, et al. Outcomes of the California ban on pharmaceutical lindane: clinical and ecologic impacts. Environ Health Perspect 2008; 116:297.
- Hipolito RB, Mallorca FG, Zuniga-Macaraig ZO, et al. Head lice infestation: single drug versus combination therapy with one percent permethrin and trimethoprim/sulfamethoxazole. Pediatrics 2001; 107:E30.
- Burgess IF, Brunton ER, French R, Burgess NA. Prevention of head louse infestation: a randomised, double-blind, cross-over study of a novel concept product, 1% 1,2-octanediol spray versus placebo. BMJ Open 2014; 4:e004634.
- 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:e35419.
- Pearlman DL. A simple treatment for head lice: dry-on, suffocation-based pediculicide. Pediatrics 2004; 114:e275.
- Pearlman D. Cetaphil cleanser (Nuvo lotion) cures head lice. Pediatrics 2005; 116:1612.
- Roberts RJ, Burgess IF. New head-lice treatments: hope or hype? Lancet 2005; 365:8.
- Lwegaba A. Shaving can be safer head lice treatment than insecticides. BMJ 2005; 330:1510.
- Resnik KS. A non-chemical therapeutic modality for head lice. J Am Acad Dermatol 2005; 52:374.
- Goates BM, Atkin JS, Wilding KG, et al. An effective nonchemical treatment for head lice: a lot of hot air. Pediatrics 2006; 118:1962.
- LIFE CYCLE
- CLINICAL MANIFESTATIONS
- DIFFERENTIAL DIAGNOSIS
- First-line treatment
- - Topical pediculicides
- Locations with low pyrethroid resistance
- - Pyrethroids
- Locations with prevalent pyrethroid resistance
- - Malathion
- - Benzyl alcohol
- - Spinosad
- - Topical ivermectin
- - Wet combing
- Refractory infestations
- - Oral ivermectin
- Other therapies
- - Dimethicone
- - Lindane
- Lindane toxicity
- - Trimethoprim-sulfamethoxazole
- - 1,2-Octanediol
- - Synthetic detergent cleanser
- - Physical methods
- RETURN TO SCHOOL
- HOUSEHOLD RECOMMENDATIONS
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS