REVIEW

Pediculosis capitis: new insights into epidemiology,diagnosis and treatment

H. Feldmeier

Received: 27 January 2012 /Accepted: 29 January 2012 /Published online: 1 March 2012# Springer-Verlag 2012

Abstract Pediculosis capitis is a ubiquitous parasitic skindisease caused by Pediculus humanus capitis. Head lice arehighly specialised parasites which can propagate only onhuman scalp and hair. Transmission occurs by direct head-to-head contact. Head lice are vectors of important bacterialpathogens. Pediculosis capitis usually occurs in small epidem-ics in play groups, kindergartens and schools. Population-based studies in European countries show highly divergingprevalences, ranging from 1% to 20%. The diagnosis of headlice infestation is made through the visual inspection of hairand scalp or dry/wet combing. The optimal method for thediagnosis of active head lice infestation is dry/wet combing.Topical application of a pediculicide is the most commontreatment. Compounds with a neurotoxic mode of action arewidely used but are becoming less effective due to resistantparasite populations. Besides, their use is restricted by safetyconcerns. Dimeticones, silicone oils with a low surface ten-sion and the propensity to perfectly coat surfaces, have apurely physical mode of action. This group of compounds ishighly effective and safe, and there is no risk that head licebecome resistant. The control of epidemics requires activecontact tracing and synchronised treatment with an effectiveand safe pediculicide.

Introduction

Pediculosis capitis is a ubiquitous parasitic skin disease. Itcauses considerable distress to affected children and their

families, and absorbs important resources from public healthinstitutions [1, 2]. There are hints that the prevalence of headlice infestation has increased globally over the last decade[3], and that the increase is the result of the massive use ofpediculicides with a neurotoxic mode of action in the pastwith the subsequent emergence and spread of resistant headlice populations [48]. This development has promptedresearch into new treatment strategies, such as pediculicidesbased on plant-derived essential oils or with a pure physicalmode of action. Based on new insights into the epidemiologyof head lice infestation and the availability of non-toxic andhighly effective drugs, a rational strategy for control exists forthe first time.

Biology

Sucking lice ( Anoplura) are ectoparasites of mammals. Thehighly specialised blood-sucking insects complete theirentire life cycle on the host. Sucking lice of primates haveundergone at least 25 million years of coevolution with theirhosts, whereas chimpanzee lice and human head/body lice lastshared a common ancestor roughly 5.5 million years ago [9].The age of the most recent common ancestor of the twoPediculus species (the head louse and the body louse) matchesthe age predicted by host divergence [9]. Reed et al. [10]suggested that the shared coevolutionary history of theanthropoid primates and their lice is a mixture of evolutionaryevents, including cospeciation, parasite duplication, parasiteextinction and host switching.

Mitochondrial DNA studies have shown that there are threeclearly divergent mitochondrial clades of P. humanus datingback up to 2 million years, each with a specific geographicdistribution [11]. Clade A comprises head lice and body liceand has a worldwide distribution. Clade B only consists of

H. Feldmeier (*)Institute of Microbiology and Hygiene,Charit University Medicine, Campus Benjamin Franklin,Hindenburgdamm 27,12203 Berlin, Germanye-mail: hermann.feldmeier@charite.de

Eur J Clin Microbiol Infect Dis (2012) 31:21052110DOI 10.1007/s10096-012-1575-0

head lice and has been detected in the Americas, Europe andAustralia [12]. Clade C is the most divergent clade and hasbeen identified only among head lice fromNepal and Ethiopia[13].

Since body lice and head lice are closely linked subspecies,they are morphologically indistinguishable [12]. Moreover, agenetic analysis did not find any differences between the twosubspecies [13]. This makes it plausible that both subspeciesalso have the same capacity as vectors for pathogens.

In fact, there is now clear evidence that Pediculus humanuscapitis can transmit Rickettsia prowazekii (the agent of louse-born epidemic typhus) and Bartonella quintana (the agent oftrench fever, endocarditis, bacillary angiomatosis and otherdisease manifestations), and, supposedly, all other pathogensfor which hitherto transmission had only been proved for P.humanus corporis [14]. In a study in rural Ethiopia, B. quin-tanawas observed in 7% of head lice and in 18% of body lice[15]. Moreover, there was a mutual exclusion of B. quintanain head or body lice in the same person. Interestingly, allpersons with head lice infected with B. quintana were fromlocations at altitudes higher 2,000 m, whereas at these alti-tudes, no body lice were infected with B. quintana [15].

The high proportion of head lice infected with importantpathogens in countries such as Ethiopia increase the oddsthat these pathogens are introduced by refugees. A study inIsrael showed that 65% of Ethiopian migrants were infestedwith head lice [16]. Whether these findings represent anactual health threat for the European population remains tobe demonstrated: neither R. prowazekii nor B. quintanacirculate in the European child population, the number ofhead lice present on the scalp of a European child is low(usually less than 10) and the minute amount of bloodingested by a single louse (

Whether head lice can be transmitted through fomites hasbeen a topic of controversy for a long while. Based on a seriesof studies in Australian children, Canyon and Speare [25]concluded that the weight of evidence is against transmissionthrough fomites.

Diagnosis

The diagnosis of head lice infestation is made through thevisual inspection of hair and scalp or by dry/wet combing. Thediagnostic accuracy of these methods has been investigatedrecently. The optimal method to diagnose historical infestation(presence only of nits/dead eggs) is visual inspection [26]. Todo so, the hair is systematically screened with the aid of anapplicator stick. Usually, the inspection is confined to fivepredilection sites: left and right temples, behind the ears andthe neck. For reasons unknown, lice prefer to cement theireggs to hair shafts in these topographic areas [27]. Anobserver-blinded study in school children showed that thesensitivity of visual inspection in detecting historical infesta-tion is 86% (95% confidence interval 8290%) and that, ifonly a few eggs/nits are present, they are overlooked by visualinspection but confirmed by wet combing [23].

The optimal method for the diagnosis of active head liceinfestation (presence of trophic stages and/or viable eggs) isdry/wet combing with a sensitivity of 90% (95% confidenceinterval 8794%) in children with low infestation intensity.The negative predictive value of this method is 99% [23].

In contrast, the sensitivity of visual inspection to diagnosean active infestation is unacceptably low, even when thewhole scalp is inspected [28]. In one study, in only 6% ofchildren screened for nymphs or adults, head lice were foundon the scalp by visual inspection, as compared to 25% aftercombing, resulting in a sensitivity of visual inspection of 22%[29]. Recent data from Germany revealed a sensitivity of 29%[23].

If wet combing is performed for a diagnostic purpose only,it is stopped when the first viable nymph/louse is detected. Ifone wants to take the therapeutic effect of wet combing as anadvantage, the hair has to be combed completely.

As adult head lice can be identified with the naked eye, andeggs/nits are easily differentiated from artefacts, the specificityof visual inspection and of detection combing should be high.However, the methods are frequently applied by people whoare not acquainted with the morphological characteristics ofhead lice/eggs and, consequently, misinterpret what they see.In the USA, for instance, only 59% of 614 samples sent to areference centre for the diagnosis of head lice infestationcontained trophic forms or eggs [30]. Debris such as dandruffand other epidermal material was found in 35% of all samples,and other arthropods (book lice, beetles, mites, bed bugs etc.)in 5%. In addition, only 53% of the specimens thought to

contain a trophic stage or a viable egg actually showed thecorresponding life stage of the parasite. This is a matter ofconcern, since potentially hazardous treatments were appliedto 62% of individuals with specimens without any lice material[30].

Therapy

Basically, three different approaches are used to eliminatehead lice: therapeutic wet combing (also named bug busting),topical application of a pediculicide and oral treatment. Phys-ical methods, such as the application of hot air, have not beenevaluated sufficiently.

The current practice is to treat with two applications 810 days apart, and to check for cure after 14 days. Recentadvances in the ex vivo development of adult head lice andtheir eggs make it possible to assess the efficacy of newcompounds in a standardised manner [31].

Oral treatment

Out of the various antihelminthic compounds and antibioticswith a pediculicidal effect, only ivermectin has been investi-gated thoroughly. A recent study in France showed that twodoses of ivermectin of 400 mg each, given 8 days apart, cured97% of patients compared to 90% of patients treated withmalathion [32]. A population-based study in South Indiashowed a significant reduction in the prevalence of head liceinfestation in school children after mass treatment with a singledose of ivermectin plus diethylcarbamazine (a drug againstworms causing lymphatic filariasis) [33]. However, althougheffective, oral ivermectin is not currently licensed for treatinghead lice.

Topical treatment: compounds with a neurotoxicmode of action

Pediculicides with a neurotoxic mode of action are eitherorganophosphates (malathion), carbamates (carbaryl), pyreth-rins (extract of chrysanthemum) or pyrethroids (syntheticderivates of pyrethrins such as permethrin, phenothrin ordeltamethrin). Some products also contain piperonyl butoxideor chlorocresol. Extensive use of these compounds has ledto the development of resistant head lice population on allcontinents [34]. Resistance has increased in frequency andgeographic extent in recent years [48]. Double and cross-resistance are frequent [3537]. Not surprisingly, recentclinical trials in Great Britain showed an unacceptable lowefficacy of permethrin, the most widely used pyrethroid[3840]. Other concerns of this group of pediculicides are

Eur J Clin Microbiol Infect Dis (2012) 31:21052110 2107

transcutaneous resorption [41], the development of hypersen-sitivity against pyrethroids [42], severe neurological complica-tions after accidental ingestion [43] and increased risk for thedevelopment of childhood leukaemia [44].

Plant-based pediculicides

Plant-based pediculicides contain mixtures of essential oilswith or without vegetal fatty acids. In vitro, several essentialoils showed higher LD50 values than -phenothrin or pyre-thrum [45]. Essential oils were also shown to be effectiveagainst permethrin-resistant head lice [46]. Heukelbach et al.[47] provide an overview on the plant extracts evaluated andthe possible mode of action of essential oils. Two productshave been assessed in randomised controlled trials. In a studyin Great Britain, Paranix, a combination of coconut, anis andylang-ylang oil, showed an efficacy of 82%; MosquitoLuse-Shampoo, a product containing soya oil and coconutoil, had an efficacy of 62% [38, 40]. Whether plant-basedpediculicides are safe has never been investigated thoroughly.

Dimeticones

Dimeticones are linear polysiloxanes and belong to the groupof synthetic silicone oils. The chain length determines theviscosity of the substance. Dimeticones are clear, colourless,odourless and hydrophobic. Dimeticones of low surface ten-sion can perfectly coat surfaces. If applied on a louse, theycoat the cuticle of the insect, enter into the spiracles (tinytracheae-like tubes protruding into the louse body) and dis-place the air needed for breathing. Two independent studieshave shown that dimeticones have a pure physical mode ofaction [48, 49]. Whereas Richling and Bckeler [49] demon-strated that the product which they investigated entered thetracheal system, displaced air and blocked oxygen supplywithin less than one minute, Burgess [48] argued that thecompound he used killed lice by the disruption of watermanagement, subsequent osmotic stress and gut rupture, andcaused death of the parasite with a delay of several hours.

Dimeticones have been used as anti-foaming agents inchildren and adults for many years. They are biochemicallyinert and are considered to be non-toxic [50, 51]. Due totheir mode of action, the development of resistant head liceis very unlikely [50].

Two dimeticones have been extensively evaluated in vitroand in randomised clinical trials. Hedrin (and other brandnames used in European countries), a 4% dimeticone solution,showed an efficacy of between 70% and 92% in studies inGreat Britain and Turkey [5254]. The efficacy was inverselyproportional to the intensity of infestation. NYDA, a mixtureof two dimeticones with different physico-chemical properties,

showed an efficacy of 97% in heavily infected Brazilianchildren [55]. The efficacy of the product did not depend onthe intensity of the infestation.

Various other pediculicides, containing dimeticone with orwithout additional compounds, are sold as over-the-counter-drugs or medicinal products in Europe. However, the efficacyclaimed by the producers is not substantiated by the scientificliterature [50].

Isopropyl myristate, an ester, also appears to have a phys-ical mode of action. A 50% solution of the compound incyclometicone cured 82% of the patients in a study in GreatBritain [39].

Recently, the ovicidal activity of various dimeticones hasbeen assessed in vitro [56]. The efficacy to kill developing liceembryos essentially depended on the physico-chemical proper-ties of the dimeticone formulation. Whereas NYDA showedan efficacy of 95% and 100% against young and mature eggs,respectively, Hedrin was not effective at all [56]. As expected,pediculicides with a neurotoxic mode of action had no signif-icant effect on developing louse embryos [56].

A dimeticone-based pediculicide with a high efficacyagainst nymphs, adults and eggs would be a good candidatefor a single-application treatment.

Control

A rational approach to control head lice among children hasto be based on the following facts:

Pediculosis capitis occurs in small epidemics in the childpopulation of educational institutions such as kindergart-ens and schools. Since children in the respective agegroups have tight social bonds and protective immunitydoes not develop, head lice can easily spread and infest aconsiderable proportion of the child population within arelatively short period of time.

An unknown number of infested individuals developpruritus of the scalp and can be diagnosed by asymptom-based approach. If infested individuals remainuntreated, they will continue to spread head lice in theinstitution. The presence of overlooked (chronic) carriersexplains why epidemics frequently reoccur in a definedchild population [42].

The diagnosis of pediculosis capitis is time-consumingand labourious, particularly when the number of licepresent is small. If only visual inspection is used, themajority of cases with an active infestation, e.g. thosewho can spread the infestation, are overlooked.

When pediculicides with a neurotoxic mode of actionare used, treatment failure is frequent [18, 36].

By consequence, the control of head lice epidemics has tobe based on three principles: active contact tracing and dry/wet

2108 Eur J Clin Microbiol Infect Dis (2012) 31:21052110

combing for diagnosis, synchronised treatment of infestedindividuals and the use of a drug with high efficacy againstnymphs/adults and eggs. The importance of synchronisedtreatment has also been demonstrated through mathematicalmodelling [57]. If supposedly infested individuals (siblings,other family members, member of play groups, other con-tacts) are also treated, transmission is interrupted with ahigh degree of certainty. In the case where dry/wet combingis not feasible in traced contacts, treatment without diagnosiscan be performed if a safe pediculicide, such as a dimeticone,is used [42].

References

1. Jahnke C, Bauer E, Feldmeier H (2008) Pediculosis capitis imkindesalter: epidemiologische und sozialmedizinische erkenntnisseeiner reihenuntersuchung von schulanfngern. Gesundheitswesen70:667673

2. Rukke BA, Birkemoe T, Soleng A, Lindstedt HH, Ottesen P (2011)Head lice prevalence among households in Norway: importance ofspatial variables and individual and household characteristics. Para-sitology 138:12961304

3. Falagas ME, Matthaiou DK, Rafailidis PI, Panos G, Pappas G(2008) Worldwide prevalence of head lice. Emerg Infect Dis14:14931494

4. Vassena CV, Mougabure Cueto G, Gonzlez Audino P, AlzogarayRA, Zerba EN, Picollo MI (2003) Prevalence and levels of permeth-rin resistance in Pediculus humanus capitis de geer (Anoplura:Pediculidae) from Buenos Aires, Argentina. J Med Entomol40:447450

5. Kasai S, Ishii N, Natsuaki M, Fukutomi H, Komagata O, KobayashiM, Tomita T (2009) Prevalence of kdr-like mutations associated withpyrethroid resistance in human head louse populations in Japan. JMed Entomol 46:7782

6. Durand R, Millard B, Bouges-Michel C, Bruel C, Bouvresse S, IzriA (2007) Detection of pyrethroid resistance gene in head lice inschoolchildren from Bobigny, France. J Med Entomol 44:796798

7. Kristensen M, Knorr M, Rasmussen AM, Jespersen JB (2006)Survey of permethrin and malathion resistance in human head licepopulations from Denmark. J Med Entomol 43:533538

8. Yoon KS, Gao JR, Lee SH, Clark JM, Brown L, Taplin D (2003)Permethrin-resistant human head lice, Pediculus capitis, and theirtreatment. Arch Dermatol 139:9941000

9. Weiss RA (2009) Apes, lice and prehistory. J Biol 8:20. doi:10.1186/jbiol114

10. Reed DL, Light JE, Allen JM, Kirchman JJ (2007) Pair of lice lost orparasites regained: the evolutionary history of anthropoid primatelice. BMC Biol 5:7. doi:10.1186/1741-7007-5-7

11. Light JE, Allen JM, Long LM, Carter TE, Barrow L, Suren G,Raoult D, Reed DL (2008) Geographic distributions and origins ofhuman head lice (Pediculus humanus capitis) based onmitochondrialdata. J Parasitol 94:12751281

12. Parola P, Fournier PE, Raoult D (2006) Bartonella quintana, lice,and molecular tools. J Med Entomol 43:787

13. Reed DL, Smith VS, Hammond SL, Rogers AR, Clayton DH(2004) Genetic analysis of lice supports direct contact betweenmodern and archaic humans. PLoS Biol 2:e340

14. Feldmeier H (2010) Lice as vectors of pathogenic microorganisms.In: Heukelbach J (ed) Management and control of head lice infesta-tions. UNI-MED Verlag, Bremen, pp 132135

15. Angelakis E, Diatta G, Abdissa A, Trape JF, Mediannikov O, RichetH, Raoult D (2011) Altitude-dependent Bartonella quintana genotypeC in head lice, Ethiopia. Emerg Infect Dis 17:23572359

16. Mumcuoglu KY, Miller J, Manor O, Ben-Yshai F, Klaus S (1993)The prevalence of ectoparasites in Ethiopian immigrants. Isr J MedSci 29:371373

17. Feldmeier H (2006) Pediculosis capitis: die wichtigste parasitosedes kindesalters. Kinder- und Jugendmedizin 4:249259

18. Willems S, Lapeere H, Haedens N, Pasteels I, Naeyaert JM, DeMaeseneer J (2005) The importance of socio-economic status andindividual characteristics on the prevalence of head lice in school-children. Eur J Dermatol 15:387392

19. Buczek A, Markowska-Gosik D, Widomska D, Kawa IM (2004)Pediculosis capitis among schoolchildren in urban and rural areasof eastern Poland. Eur J of Epidemiol 19:491495

20. Courtiade C, Labrze C, Fontan I, Taeb A, Maleville J (1993) Lapdiculose du cuir chevelu: enquete par questionnaire dans quatregroupes scolaires de lacadmie de Bordeaux. Ann DermatolVenereol 120:363368

21. Kokturk A, Baz K, Bugdayci R, Sasmaz T, Tursen U, Kaya TI,Ikizoglu G (2003) The prevalence of pediculosis capitis in school-children in Mersin, Turkey. Int J Dermatol 42:694698

22. Downs AMR, Stafford KA, Coles GC (1999) Head lice: preva-lence in schoolchildren and insecticide resistance. Parasitol Today15:14

23. Jahnke C, Bauer E, Hengge UR, Feldmeier H (2009) Accuracy ofdiagnosis of pediculosis capitis: visual inspection vs wet combing.Arch Dermatol 145:309313

24. Bauer E, Jahnke C, Feldmeier H (2009) Seasonal fluctuations ofhead lice infestation in Germany. Parasitol Res 104:677681

25. Canyon DV, Speare R (2010) Indirect transmission of head lice viainanimate objects. Open Dermatol J 4:7276

26. Feldmeier H (2010) Diagnosis of head lice infestations: anevidence-based review. Open Dermatol J 4:6971

27. Nash B (2003) Treating head lice. BMJ 326:1256125728. De Maeseneer J, Blokland I, Willems S, Vander Stichele RH,

Meersschaut F (2000) Wet combing versus traditional scalpinspection to detect head lice in schoolchildren: observationalstudy. BMJ 32:11871188

29. Mumcuoglu KY, Friger M, Ioffe-Uspensky I, Ben-Ishai F, Miller J(2001) Louse comb versus direct visual examination for the diagnosisof head louse infestations. Pediatr Dermatol 18:912

30. Pollack RJ, Kiszewski AE, Spielman A (2000) Overdiagnosis andconsequent mismanagement of head louse infestations in NorthAmerica. Pediatr Infect Dis J 19:689693

31. Sonnberg S, Oliveira FA, de Melo ILA, de Melo Soares MM,Becher H, Heukelbach J (2010) Ex vivo development of eggs fromhead lice (Pediculus humanus capitis). Open Dermatol J 4:8289

32. Chosidow O, Giraudeau B, Cottrell J, Izri A, Hofmann R, MannSG, Burgess I (2010) Oral ivermectin versus malathion lotion fordifficult-to-treat head lice. N Engl J Med 362:896905

33. Munirathinam A, Sunish IP, Rajendran R, Tyagi BK (2009) Impactof ivermectin drug combinations on Pediculus humanus capitisinfestation in primary schoolchildren of south Indian rural villages.Int J Dermatol 48:12011205

34. Elston DM (2003) Drug-resistant lice. Arch Dermatol 139:1061106435. Picollo MI, Vassena CV, Mougabure Cueto GA, Vernetti M, Zerba

EN (2000) Resistance to insecticides and effect of synergists onpermethrin toxicity in Pediculus capitis (Anoplura: Pediculidae)from Buenos Aires. J Med Entomol 37:721725

36. Bailey AM, Prociv P (2000) Persistent head lice following multipletreatments: evidence for insecticide resistance in Pediculus humanuscapitis. Australas J Dermatol 41:250254

37. Hunter JA, Barker SC (2003) Susceptibility of head lice (Pediculushumanus capitis) to pediculicides in Australia. Parasitol Res 90:476478

Eur J Clin Microbiol Infect Dis (2012) 31:21052110 2109

38. Burgess IF, Kay K, Burgess NA, Brunton ER (2011) Soya oil-based shampoo superior to 0.5% permethrin lotion for head louseinfestation. Med Devices Evidence Res 4:3542

39. Burgess IF, Lee PN, Brown CM (2008) Randomised, controlled,parallel group clinical trials to evaluate the efficacy of isopropylmyristate/cyclomethicone solution against head lice. Pharmaceut J280:371375

40. Burgess IF, Brunton ER, Burgess NA (2010) Clinical trial showingsuperiority of a coconut and anise spray over permethrin 0.43%lotion for head louse infestation, ISRCTN96469780. Eur J Pediatr169:5562

41. Tomalik-Scharte D, Lazar A, Meins J, Bastian B, Ihrig M, WachallB, Jetter A, Tantcheva-Por I, Mahrle G, Fuhr U (2005) Dermalabsorption of permethrin following topical administration. Eur JClin Pharmacol 61:399404

42. Feldmeier H, Jahnke C (2010) Pediculosis capitis. Epidemiologie,Diagnose und Therapie. Pdiatrische Praxis 76:359370

43. [No authors listed] (2009) Topische Therapie bei Kopflusen. DerArzneimttelbrief 43:8186

44. Menegaux F, Baruchel A, Bertrand Y, Lescoeur B, Leverger G,Nelken B, Sommelet D, Hmon D, Clavel J (2006) Householdexposure to pesticides and risk of childhood acute leukaemia.Occup Environ Med 63:131134

45. Yang YC, Lee HS, Clark JM, Ahn YJ (2004) Insecticidal activity ofplant essential oils against Pediculus humanus capitis (Anoplura:Pediculidae). J Med Entomol 41:699704

46. Gonzalez Audino P, Vassena C, Zerba E, Picollo M (2007)Effectiveness of lotions based on essential oils from aromaticplants against permethrin resistant Pediculus humanus capitis.Arch Dermatol Res 299:389392

47. Heukelbach J, Canyon DV, Speare R (2007) The effect of naturalproducts on head lice: in vitro tests and clinical evidence. J PedInfect Dis 2:6776

48. Burgess IF (2009) The mode of action of dimeticone 4% lotionagainst head lice, Pediculus capitis. BMC Pharmacol 9:3.doi:10.1186/1471-2210-9-3

49. Richling I, Bckeler W (2008) Lethal effects of treatment with aspecial dimeticone formula on head lice and house crickets

(Orthoptera, Ensifera: Acheta domestica and Anoplura, phthirap-tera: Pediculus humanus). Insights into physical mechanisms.Arzneimittelforschung 58:248254

50. Heuckelbach J, Oliveira FA, Richter J, Hussinger D (2010)Dimeticone-based pediculicides: a physical approach to eradicatehead lice. Open Dermatol J 4:7781

51. Nair B; Cosmetic Ingredients Review Expert Panel (2003) Finalreport on the safety assessment of stearoxy dimethicone, dimethi-cone, methicone, amino bispropyl dimethicone, aminopropyl dime-thicone, amodimethicone, amodimethicone hydroxystearate,behenoxy dimethicone, C24-28 alkyl methicone, C30-45 alkylmethicone, C30-45 alkyl dimethicone, cetearyl methicone, cetyldimethicone, dimethoxysilyl ethylenediaminopropyl dimethicone,hexyl methicone, hydroxypropyldimethicone, stearamidopropyldimethicone, stearyl dimethicone, stearyl methicone, and vinyldime-thicone. Int J Toxicol 22:1135

52. Kurt O, Balciolu IC, Burgess IF, Limoncu ME, GirginkardelerN, Tabak T, Muslu H, Ermi O, Sahin MT, Bilac C, Kavur H,Ozbel Y (2009) Treatment of head lice with dimeticone 4% lotion:comparison of two formulations in a randomised controlled trial inrural Turkey. BMC Public Health 9:441

53. Burgess IF, Lee PN, Matlock G (2007) Randomised, controlled,assessor blind trial comparing 4% dimeticone lotion with0.5% malathion liquid for head louse infestation. PLoS One2:e1127

54. Burgess IF, Brown CM, Lee PN (2005) Treatment of head louseinfestation with 4% dimeticone lotion: randomised controlledequivalence trial. BMJ 330:14231426

55. Heukelbach J, Pilger D, Oliveira FA, Khakban A, Ariza L, FeldmeierH (2008) A highly efficacious pediculicide based on dimeticone:randomized observer blinded comparative trial. BMC Infect Dis8:115. doi:10.1186/1471-2334-8-115

56. Heukelbach J, Sonnberg S, Becher H, Melo I, Speare R, OliveiraFA (2011) Ovicidal efficacy of high concentration dimeticone: anew era of head lice treatment. J Am Acad Dermatol 64:e61e62

57. Laguna MF, Risau-Gusman S (2011) Of lice and math: usingmodels to understand and control populations of head lice. PLoSOne 6:e21848. doi:10.1371/journal.pone.0021848

2110 Eur J Clin Microbiol Infect Dis (2012) 31:21052110

Copyright of European Journal of Clinical Microbiology & Infectious Diseases is the property of SpringerScience & Business Media B.V. and its content may not be copied or emailed to multiple sites or posted to alistserv without the copyright holder's express written permission. However, users may print, download, oremail articles for individual use.