Vlaamsezorgkas.be

Australasian Journal of Dermatology (2000) 41, 209–212
David de Berker1 and Rodney Sinclair2
1Bristol Dermatology Centre, Bristol Royal Infirmary, Bristol, United Kingdom, 2Department of Dermatology, St. Vincent’s Hospital, Fitzroy, Victoria, Australia into three categories: biological resistance to a range of chemical insecticides; practical and social problems with the application of physical therapies; and re-infestation. It is Dermatologists are the nominal experts in the notable that Bailey and Prociv felt the last aspect was not management of head lice in Australia, yet many contributory to their protracted problem.
dermatologists infrequently treat patients with thiscondition. Most people are managed in the com- BIOLOGICAL RESISTANCE
munity by school nurses, local council health officers,pharmacists, paediatricians or general practitioners.
Reports of resistance began to emerge from all over the Only a small number will present to the dermatologist world4–12 soon after the introduction of insecticides for the and commonly these patients will have tried a variety treatment of head lice. In the 1980s, dichlorodiphenyl of treatments and failed to respond. Resistance is trichloroethane (DDT)4 was the first agent suspected, followed reported to all of the currently available insecticide by lindane5,6,12 and latterly malathion,6–12 permethrin6,12 and treatments and this makes management of this com- pyrethrins with piperonyl butoxide8 (Table 1). Some lice mon community-acquired infestation more involved.
now appear to be multiply resistant, with levels of in vivo Key words: cotrimoxazole, DDT, ivermectin, lin-
resistance to permethrin rising to 87% in an urban setting such dane, malathion, pediculosis capitis, permethrin,
as Bristol, England, with coincident resistance to malathion piperonyl butoxide, public health, pyrethrins, resis-
of 64%.12 These figures represent children undergoing tance, treatment.
supervised applications by medical staff. Head lice harvestedfrom the same group of children were tested in vitro to representative concentrations of both insecticides and to DDT and carbaryl. The patterns of resistance mimicked the clinical resistance in the first three, with only carbaryl The article in this issue by Bailey and Prociv1 on head lice will allowing survival of less than 5% of tested lice. Permethrin, strike a familiar note with parents and doctors alike. Their pyrethrins with piperonyl butoxide and malathion are avail- account is similar to that given by another medical family able over the counter in the United Kingdom (UK), as in many other parts of the world, and these patterns of resistance are The natural history of infestation has been described in a volunteer to continuous exposure to lice bites.3 The sequence Cotrimoxazole has been reported as an effective treatment of skin reactions were: phase 1, no clinical symptoms; phase for head lice.13 The putative mechanism of action is on 2, pruritic papules; phase 3, immediate wheal formation after symbiotic Gram-negative bacteria in the gut of the louse that bites, followed by an intensely itchy delayed papular eruption; are required for digestion of ingested blood products.
phase 4, papular reaction with diminished skin reactivity and Unfortunately, it is only effective against adult and nymphal mild pruritus. Healed bite reactions reappeared when other stages but not the eggs, so prolonged courses are required.14 parts of the skin were again exposed to lice.
Newer agents such as ivermectin15 may hold promise, but Head lice are seldom cited as a health risk, but rather a there are reports of fatal toxicity in veterinary use and a fear source of domestic frustration and upheaval in the school, of increased susceptibility to neurological side-effects in home and doctor’s office. The difficulties in treatment fall children.16 A 1% shampoo formulation warrants furtherinvestigation.17 However, the adaptability of head lice is well proven and it Correspondence: Rodney Sinclair, Department of Dermatology, St is likely that resistance will also develop in time to these new Vincent’s Hospital, Fitzroy, Vic. 3065, Australia. Email: sinclair@svhm.org.au agents. It is this setting that makes physical treatments an Rodney Sinclair, FACD. David de Berker, MRCP.
PHYSICAL THERAPIES AND THEIR
lence of infestation in those schools had risen.20 This could APPLICATION
represent a failure of the educational process, poor motivationwithin the family, or some other biological or social process Physical therapies are legion and are poorly studied. They resulting in increased infestation. Limited trials on a modest utilize a range of approaches; the most popular is extraction scale suggest that combing might work, but it may still be of eggs and lice with a fine comb. Metal combs are better than difficult to achieve success across the board.
plastic and it is useful to have a lubricant (such as conditioner)to assist clearing knots and to make the process more com-fortable. Combing regimens are not specific but are designed RE-INFESTATION AND SCHOOL EXCLUSION
to remove mature lice which might otherwise lay eggs and One modality that combines physical treatment and moti- perpetuate the life cycle. If no adult lice have been found for vation is school exclusion. This is common in schools in 2 weeks, it is likely that the cycle has been broken. Combing Australia and the United States of America. For the strategy to can be undertaken every one to 3 days.
be successful, all children in the class must be evaluated by Although there are reputable claims that this method is health professionals after the reporting of a single case. All effective18 there are no good randomized or controlled trials.
those affected must be excluded. Exclusion could be overnight As Bailey and Prociv point out, it is difficult to comb effectively during treatment21 or for 2 weeks, depending on whether the and to be sure that all the lice on the scalp are found when aim is to ensure therapy or cure. Theoretically, re-admission the hair is long and thick, and residual lice could easily result is only after clearance has been confirmed by examination.
in treatment failure.1 Eighty percent of infestations represent There is no recent evidence that exclusion is effective in a load of only 1–10 lice, which means that it is easy to miss controlling head lice in school children. Possibly this is because it is difficult and expensive to fully enforce. Failure Alternatives include killing the adults with an electric is likely in areas of pharmacological resistance, where comb that discharges a small shock, shaving the hair, or using re-infestation occurs within the family or where motivation agents such as petrolatum, olive oil or even mayonnaise that is lacking and family order less defined. Some children could suffocate the lice. To suffocate the lice, a generous quantity of continue to be excluded for prolonged periods, based on social grease is massaged into the scalp and over the hair. It is then factors that reduce the chances of effective treatment. These washed out over successive nights with shampoo. This is time kinds of consideration must bring exclusion into question and consuming, particularly when the hair is long or thick.
it has been challenged by some authorities.21 Petrolatum is, of course, not to be confused with petrol orkerosene; both have been advocated, but are dangerouslyflammable, a problem shared with alcohol-based topical ECONOMIC CONSIDERATIONS
products that also have the potential for exacerbating asthma.
From the account of Bailey and Prociv,1 it seems that a So what is the cost? There are the costs of chemicals, family combination of shorter hair and diligent combing was time, and potential social and educational costs. The pharma- eventually successful. From the domestic angle, it is difficult ceutical industry is likely to continue to produce new chem- to get young children to be still for 20 min each, while the wet icals that will gradually increase in cost and provide only or lubricated hair is combed with a fine nit comb, a procedure temporary benefit. Prescriptions for pediculocides in England that may have to be repeated for weeks on end.
rose 500% between 1985 and 1995, reflecting a combination In principal, shaving, petrolatum or combing might be 100% of resistance and increased prevalence.22 Families are variable effective. However, on a population basis, the results are less in their ability to apply treatments, with a mixture of poor encouraging. Twelve months after an educational programme information and confusion complicating the situation. Sources to describe ‘nit busting’ in local primary schools, the preva- of clear information may not always be to hand for clinicianor patient (Table 2). The emerging patterns of resistance Reports of insecticide resistance in the treatment of head Sources of information on the Internet, including patient http://www.hsph.harvard.edu/headlice.html Well balanced, comprehensive website useful to clinicians Designed by an interest group with a heavy emphasis on eradication. Contains an aggressive protocol for combing and http://medinfo.co.uk/conditions/headlice.html Background information and a good description of combing ‘Head lice’ search at this site yields several pages, includingprofessional notes and a multilingual patient information DDT, Dichlorodiphenyl trichloroethane; Ref., reference number.
sheet. No mention of combing or insecticide resistance International surveys of head lice infestation in school 2. Dawes M, Hicks NR, Fleminger M et al. Treatment for head lice.
BMJ 1999; 318: 385–6.
3. Mumcuoglu KY, Klaus S, Kafka D, Teiler M, Miller J. Clinical observations related to head lice infestation. J. Am. Acad. Dermatol. 1991; 25: 248–51.
4. Sinniah B, Sinniah D. Resistance of head louse (Pediculus humanus capitis de Geer) to DDT in Malaysia. Trans. R. Soc. Trop. Med. Hyg. 1982; 76: 72–4.
5. Kucirka SA, Parish LC, Witkowski JA. The story of lindane resistance and head lice. Int. J. Dermatol. 1983; 22: 551–5.
6. Goldsmid JM. Head louse treatment. Is there an insecticide resistance problem? Med. J. Aust. 1990; 153: 233–4.
7. Rupes V, Moravec J, Chmela J, Ledvinka J, Zelenkova J. A resistance of head lice (Pediculus capitis) to permethrin in Czech
Republic. Cent. Eur. J. Public Health 1995; 3: 30–2 (English
mean that last year’s literature may be misleading. Although a systematic review23 concluded permethrin was the only drug 8. Burgess IF, Brown CM, Peock S, Kaufman J. Head lice resistant to be supported on the basis of the evidence, it is also the drug to pyrethroid insecticides in Britain. BMJ 1995; 311: 604–8.
for which there is most evidence of resistance. In this partic- 9. Mumcuoglu KY, Hemingway J, Miller J et al. Permethrin resistance ular review, other drugs, such as carbaryl, were excluded in the head louse Pediculus capitis from Israel. Med. Vet. Entomol.
1995; 9: 427–32.
because of lack of studies, not evidence of lack of efficacy.23 10. Picollo MI, Vassena CV, Casadio AA, Massimo J, Zerba EN.
Can head lice spread serious diseases? Impetigo may be a Laboratory studies of susceptibility and resistance to insecticides complication. Where typhus is prevalent, as in some African in Pediculus capitis (Anoplura; Pediculidae). J. Med. Entomol. 1998; countries, body lice may contain Rickettsia prowazekii.24 35: 814–17.
Although mentioned in a recent review,25 there is no modern 11. Pollack RJ, Kiszewski A, Armstrong P et al. Differential permethrin English language literature concerning head lice as a vector susceptibility of head lice sampled in the United States and Borneo.
Arch. Pediatr. Adolesc. Med. 1999; 153: 969–73.
for typhus or trench fever. To a great extent, the problem, if it 12. Downs AMR, Stafford KA, Harvey I, Coles GC. Evidence for is a problem, is seen as one affecting the school and educa- double resistance of permethrin and malathion in head lice. tional process. Data from schools in different parts of the Br. J. Dermatol. 1999; 141: 508–11.
world26–29 illustrate that infestation is common (Table 3).
13. Burns DA. Action of cotrimoxazole on head lice. Br. J. Dermatol. Within Australian schools, infestation rates of 72% and zero 1987; 117: 399–400.
have been reported in separate classrooms of the same 14. Morsy TA, Ramadan NI, Mahmoud MS, Lashen AH. On the efficacy of co-trimoxazole as an oral treatment for pediculosis school.26 Perhaps the classroom is where the problem should capitis infestation. J. Egypt. Soc. Parasitol. 1996; 26: 73–7.
be tackled. If the efficacy of combing could be established, in 15. Burkhart CG, Burkhart CN, Burkhart KM. An assessment of endemic areas this cheap and non-toxic treatment could be topical and oral prescription and over the counter treatments for headlice. J. Am. Acad. Dermatol. 1998; 38: 979–82.
Until this becomes the case, an approach to treatment 16. Burkhart CN, Burkhart CG. Another look at ivermectin in the could be an initial treatment with a pediculocide alone or treatment of scabies and head lice. Int. J. Dermatol. 1999; 38:
together with daily combing, depending on preference.30 The 17. Youssef MY, Sadaka HA, Eissa MM, el-Ariny AF. Topical appli- pediculocide could be permethrin or malathion or pyrethrins cation of ivermectin for human ectoparasites. Amer. J. Trop. Med. with piperonyl butoxide, depending on local experience. If Hyg. 1995; 53: 652–3.
there is treatment failure, a different pediculocide should 18. Lewendon G. Head lice can be controlled without application of be used, with carbaryl representing the agent with least insecticide lotions. BMJ 1999; 318: 385–6.
reported resistance. Alternatively, combing alone could be 19. Fan PC, Chung WC, Kuo CL et al. Evaluation of efficacy of four encouraged where the situation suggests that it will be done pediculocides against head louse (Pediculus capitis) infestation.
Kao Hsiung I Hsueh Ko Hsueh Tsa Chih 1992; 8: 255–65.
diligently. In all cases, combing should be used as 20. Downs AMR, Stafford KE, Stewart Coles GC. Factors that may part of scalp assessment and continued surveillance of the influencing the prevalence of head lice in British school children.
affected child and other family members. In resistant cases, Pediatr. Dermatol. 2000; 17: 72–4.
cotrimoxazole or ivermectin can be used. Patients can be 21. Department of Human Services, Victoria.http://www.dhs.vic.gov.
referred to websites with reasonable advice, or material can au/phb/hprot/inf_dis/bluebook/pedicul.htm. 2000.
be downloaded for dissemination by the health professional 22. Harvard School of Public Health. http://www.hsph.harvard.edu/ (Table 2). This includes detailed advice on combing and treat- 23. Vander Stichele RH, Dezeure EM, Bogaert MG. Systematic review ment of potential fomites. The latter are not a major problem of clinical efficacy of topical treatments forhead lice. BMJ 1995; and a hot wash of bedding linen and clothes should normally 311: 604–8.
24. Roux V, Raoult D. Body lice as tools for diagnosis and surveillance of re-emerging diseases. J. Clin. Microbiol. 1999; 37: 596–9.
25. Chosidow O. Scabies and pediculosis. Lancet 2000; 355: 819–26.
26. Speare R, Buettner PG. Head lice in pupils of a primary school in
REFERENCES
Australia and implications for control. Int. J. Dermatol. 1999; 38:
285–90.
1. Bailey A, Prociv P. Persistent head lice following multiple treat- 27. Downs AMR, Stafford KA, Coles GC. Head lice: Prevalence in ments: Evidence for insecticide resistance in Pediculus humanus schoolchildren and insecticide resistance. Parasitol. Today. 1999; capitis. Australas. J. Dermatol. 2000; 41: 250–4.
15: 1–3.
28. Hong HK, Kim CM, Lee JS, Lee WJ, Yang YC. Infestation rate of capitis) infestation among inhabitants of the Niger Delta. Trop. head lice in primary school children in Inchon, Korea. Korean J. Med. Parasitol. 1985; 36: 140–2.
Parasitol. 1995; 33: 243–4 (English abstract).
30. Therapeutic Guidelines Limited. Therapeutic Guidelines: Derma- 29. Arene FO, Ukaulor AL. Prevalence of head louse (Pediculus tology, v.1. Melbourne: Therapeutic Guidelines Ltd, 1999.

Source: http://vlaamsezorgkas.be/uploadedFiles/NLsite/Preventie/Kinderen_en_jongeren/Luizen/Ouders/deberker-00-2.pdf