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Head lice - Management
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Overview of management

  • Check for head lice by detection combing and treat the person only if a live head louse is found.
  • Treat all affected household members simultaneously.
  • Depending on the preference of the individual or parent and on the treatment history, treat with:
    • Dimeticone 4% lotion (Hedrin®).
    • Wet combing using the Bug Buster® comb and method.
    • Isopropyl myristate and cyclomethicone solution (Full Marks Solution®).
    • Coconut, anise, and ylang ylang spray (Lyclear SprayAway®).
    • Malathion 0.5% aqueous liquid.
  • All treatments need more than one treatment session.
  • No treatment can guarantee success.
  • Treatment has the best chance of success if it is performed correctly and if all affected household members are treated on the same day.
  • Advise people to check whether treatment was successful by detection combing on day 2 or day 3 after completing a course of treatment, and again after an interval of 7 days (day 9 or day 10 after completing a course of treatment).

How should I treat a confirmed head louse infestation?

  • Treat the person only if a live head louse is found.
  • Advise all household members to check for head lice using wet or dry detection combing.
  • Ensure all affected individuals in a household are treated simultaneously.
  • Choice of treatment depends on the preference of the individual or parent and what has been previously tried.
    • Treatment has most chance of success if it is applied or undertaken correctly and if all affected individuals in the household are treated simultaneously.
  • There is no need to wash clothing or bedding that has been in contact with lice.
  • Treatment options include:
    • Dimeticone 4% lotion (Hedrin® lotion), a physical insecticide.
      • Suitable for all ages, those with skin conditions, and those with asthma. It cannot be purchased over-the-counter for children younger than 6 months of age.
      • It should be applied twice, with 7 days between applications. Dimeticone is left on the hair and scalp for 8 hours or overnight, and is then washed out using shampoo.
    • Wet combing using the Bug Buster® comb and method.
      • Suitable for all ages, those with skin conditions, and those with asthma.
      • Unlike other treatment options, the Bug Buster® comb is reusable; one comb can be used to treat the whole family.
      • Treatment involves methodically combing wet hair with the fine-toothed Bug Buster® comb to remove lice. This is undertaken for four sessions over 2 weeks. Wet combing should be continued until no full-grown lice have been seen for three consecutive sessions.
    • Isopropyl myristate and cyclomethicone (Full Marks Solution®), a physical insecticide.
      • Suitable for those with asthma.
      • Not suitable for children younger than 2 years of age or people with skin conditions.
      • It should be applied twice, with 7 days between applications. It is left in place for 10 minutes. The hair is then systematically combed with a fine-toothed comb to remove lice and is then washed using shampoo to remove the solution.
    • Coconut, anise, and ylang ylang spray (Lyclear SprayAway®), a physical insecticide.
      • Not suitable for children younger than 2 years of age, people with skin conditions, or those with asthma.
      • It should be applied twice, with 7 days between applications. The spray is left in place for 15 minutes. The hair is then washed using shampoo to remove the spray, and then systematically combed with a fine-toothed comb to remove lice.
    • Malathion 0.5% aqueous liquid, a traditional insecticide.
      • Suitable for all ages and those with skin conditions. It cannot be purchased over-the-counter for children younger than 6 months of age.
      • It should be applied twice, with 7 days between applications. The insecticide is applied to the hair from the roots to the tips, left on the hair and scalp for 12 hours or overnight, and then washed out using shampoo.
  • For further information to assist with the choice of treatment, see Treatment options: advantages and disadvantages.
Basis for recommendation

Simultaneous treatment of all affected household contacts

  • The recommendation to treat all infested household contacts simultaneously is based on expert opinion [Ibarra et al, 2007; PHMEG, 2008]. Reinfestation from close contacts is a common cause of treatment failure.

Advice on hygiene measures

  • There is no need to wash clothing or bedding that has been in contact with lice, because head lice that fall off the head (for example onto hats or pillows) are likely to die soon [Nash, 2003; DH, 2005; HPA, 2008].

Choice of treatment

  • There is limited evidence to support the effectiveness of each treatment option recommended. No option is clearly superior or inferior to the others in terms of effectiveness and there are advantages and disadvantages for each method, and no method can guarantee success. The choice of a particular treatment strategy will depend on individual or parent preference, and success or failure with previous treatments.
  • Products with a short contact time have previously not been recommended because, for traditional insecticides, a short application time is thought to be insufficient to allow the product to exert its effect, which in turn is thought to contribute to insecticide resistance. Although both isopropyl myristate (Full Marks Solution®) and coconut, anise, and ylang ylang spray (Lyclear SprayAway®) have short contact times, their physical mode of action mean that a longer contact time is unlikely to be needed, provided the product is applied correctly.

Number of treatment sessions

  • The recommendation for two applications of traditional or physical insecticide, 7 days apart, is based on expert opinion [PHMEG, 2008]. The second application of traditional or physical insecticide is intended to kill nymphs emerging from eggs that survived the first application. One formulation of malathion aqueous liquid (Derbac-M®) is now licensed for use as two treatments, 7 days apart.
  • The recommendation to continue wet combing until no full-grown lice have been seen at three consecutive sessions is to ensure that that reinfestation is recognized, and that nymphs are removed shortly after hatching (i.e. before they reach maturity and become able to reproduce) [Ibarra, 1998].

Treatments that are not recommended

  • Permethrin is not recommended because there are concerns that a 10-minute contact time is not long enough for the product to be effective, and because there is evidence of resistance to permethrin in the UK. A recent randomized controlled trial conducted in the UK reported a cure rate of only 19% with permethrin 1% cream rinse [Burgess et al, 2008].
  • Phenothrin and carbaryl are no longer available in the UK.
  • Insecticide shampoos are not recommended because there are concerns that they become too dilute when used to be effective [Burgess, 2001; PHMEG, 2008; BNF 57, 2009].
  • Hedrin® solution, gel, or spray (dimeticone 4%). Hedrin® Once liquid and gel are registered as Class 1 medical devices in the UK. They are not listed in the Drug Tariff and so cannot be prescribed on FP10 [Prescription Pricing Division, 2010]. Hedrin ® solution and spray (licensed medicinal products) are also not included. CKS found no published randomized controlled trials studying the efficacy of these formulations of dimeticone in eradicating head lice.
  • NYDA® (dimeticone 92% spray) is registered as a Class 1 medical device in the UK. It is not listed in the Drug Tariff and so it cannot be prescribed on FP10 [Prescription Pricing Division, 2009]. CKS found one randomized controlled trial studying the efficacy of an identical strength formulation in eradicating head lice.
  • Nitty Gritty NitFree comb®, Nitcomb–S1®, Nitcomb–M2® (all metal combs) are all listed in the Drug Tariff and can, therefore be prescribed on FP10. However, CKS found no randomized controlled trials evaluating their efficacy in removing head lice. In addition, CKS expert reviewers recommend that metal nit combs such as these are not suitable for use as louse detection combs. Combs primarily for nit removal must have teeth less than the width of a nit apart to exert traction. This is too close for louse detection because lice trapped between the teeth remain unseen and can be combed back onto the head unharmed [Ibarra, 2008].
  • Lice Attack® (a coconut oil shampoo) is registered as a Class 1 medical device in the UK. It is not listed in the Drug Tariff and so it cannot be prescribed on FP10 [Prescription Pricing Division, 2009]. CKS found no published randomized controlled trials studying its efficacy in eradicating head lice.
  • Nitlotion® (contains coconut oil) is registered as a Class 1 medical device in the UK and can be prescribed on FP10 [Prescription Pricing Division, 2009]. However, CKS found no published randomized controlled trials studying its efficacy in eradication of head lice.
  • Dove® hair conditioner is not recommended. There is an anecdotal report that Dove® hair conditioners have been used to treat head lice [Eames, 2004]. These hair conditioners contain a low concentration of dimethiconol, a silicone polymer. However, CKS found no randomized trials supporting the use of this or other hair conditioners for the treatment of head lice.
  • Electric combs are not recommended. Expert consensus is that they should not be used because they are expensive, they can pose a safety risk if used incorrectly, and there is a lack of evidence for their efficacy [PHMEG, 2008].
  • Essential oil-based treatments and herbal remedies are not recommended unless their safety and efficacy has been evaluated in randomized controlled trials.
    • Essential oil-based treatments and herbal remedies should not be assumed to be safe because they are 'natural'.
    • There is some evidence from in vitro studies that some essential oils (such as tea tree oil, eucalyptus oil, lavender oil, peppermint oil, neem oil) have some activity against head lice [Gonzalez Audino et al, 2007]. However, most have not been evaluated in randomized controlled trials, and safety data are sparse.
    • Products containing different percentages of the essential oil and different excipients cannot be assumed to have similar efficacy.
    • Lyclear SprayAway® (prescribable in the UK), which contains coconut and anise oil, was found to be effective in a single randomized controlled trial.
    • One specific formulation of eucalyptus 11% solution marketed in Australia has been shown in a randomized clinical trial to be effective against head lice, although there are several methodological problems with this study that could have led to bias [Greive et al, 2007].
    • Many products marketed as wet combing aids contain essential oils; but there are no randomized controlled trials that assess their efficacy or safety.
    • Vinegar, isopropyl alcohol, olive oil, mayonnaise, melted butter, and petroleum jelly have been found to be ineffective in a laboratory study [Takano-Lee et al, 2004].

How should I treat a woman with head lice who is pregnant or breastfeeding?

  • For women who are pregnant or breastfeeding, treat head lice with wet combing or dimeticone lotion.
  • If a traditional insecticide is required as an alternative in treatment failure, malathion is recommended.
Basis for recommendation

Treatments recommended for women who are pregnant or breastfeeding

  • Wet combing might be preferred by some women as it does not involve any chemical treatment other than conditioner.
  • However, dimeticone has a well-established safety profile in cosmetics, and is licensed for use in pregnancy and breastfeeding [MHRA, 2005].
  • Both treatments are viable options, and remove the small potential risk of exposing the fetus or infant to a traditional insecticide.
  • However, if a traditional insecticide is thought to be necessary during pregnancy, the National Teratology Information Service (NTIS) currently recommends malathion, because it is poorly absorbed and rapidly eliminated (telephone 0191 232 1525 for further information) [NTIS, 2008]. The manufacturer also states that malathion is not known to be harmful when used during breastfeeding [ABPI Medicines Compendium, 2008].

Treatments not recommended for women who are pregnant or breastfeeding

  • Isopropyl myristate and cyclomethicone (Full Marks® solution) and coconut, anise, and ylang ylang spray (Lyclear SprayAway®) are not recommended for use in pregnancy or breastfeeding due to a lack of safety data [ABPI Medicines Compendium, 2009; Chefaro UK Ltd, 2009].

How should people check that treatment was successful?

  • Insecticide treatment (physical or traditional)
    • Advise people to check whether treatment was successful by detection combing on day 2 or day 3 after completing a course of treatment, and again after an interval of 7 days (day 9 or day 10 after completing a course of treatment).
      • Treatment has been successful if no lice are found at both sessions.
      • The presence of only nits (eggs) does not indicate treatment failure.
      • Itching can persist for days to weeks after head lice eradication.
    • If treatment has been repeated because the first treatment course was unsuccessful:
      • Advise people to consider detection combing 5 days after the first application of treatment, and 2 days after the second application of treatment, and again after a further 7 days.
  • Wet combing using the Bug Buster® comb and method
    • The Bug Buster® comb and method has been successful if no lice are found on day 17.
    • If lice are found on day 17, continue use of the Bug Buster® comb until no full-grown lice have been found on three consecutive sessions.
Basis for recommendation

These recommendations are based on the following:

  • There is evidence that none of the treatment options for head lice can guarantee success.
  • Since no treatment for head lice is completely ovicidal (it is not known whether physical insecticides have any ovicidal activity), it is possible that an egg laid on the morning of either treatment session could survive treatment and hatch a live head louse after the completion of a course of treatment [Lebwohl et al, 2007]. The average time from lay to hatch is 7 days, but longer intervals of up to 12 days between lay and hatch have been observed in laboratory studies.
  • Opinion from CKS expert reviewers was divided regarding the length of time itch may persist after successful treatment. Some reviewers suggest it is a few days, whilst others suggest that itch may persist for 2–3 weeks after successful eradication.
  • Some CKS expert reviewers advise that people using a traditional or physical insecticide should use an additional detection combing session on day 5 after the first application of treatment. The additional check on day 5 allows removal of nymphs that have hatched from eggs which survived the first treatment session before they can become mature adults.

How should I manage confirmed unsuccessful treatment?

  • Advise that household members, close family, and close friends (both adults and children) should be assessed using detection combing to identify possible sources of reinfestation.
  • Check whether treatment was used correctly, as poor adherence increases the risk of treatment failure.
    • For physical or traditional insecticides:
      • Check that the following were used: two treatments, correct application technique, correct application time, and sufficient volume of product to cover hair adequately.
      • Consider the possibility of resistance to a traditional insecticide, such as malathion or permethrin.
    • For wet combing:
      • Check that the following were used: the correct type of comb (for example a Bug Buster®), correct combing technique, sufficient duration of combing session, and sufficient combing sessions.
  • Repeat the same treatment or switch to a different treatment. The choice of treatment will depend on:
    • The preference of the person or child's parent.
    • Whether resistance to a traditional insecticide is suspected.
  • Whichever treatment strategy is chosen, ensure that all affected household contacts are again treated simultaneously. Other affected close contacts should also be treated without delay to reduce the risk of reinfestation.
Basis for recommendation

The recommended strategy for dealing with recurrent head lice or persistence of head lice after treatment is based on expert opinion [PHMEG, 2008].

  • There is limited evidence to support the effectiveness of each treatment option and there are advantages and disadvantages to all methods. No option is clearly superior or inferior to the others, and none can guarantee success. The choice of a particular treatment strategy will depend on individual or parent preference.
  • Since no treatment for head lice is completely ovicidal, it is possible that an egg laid on the morning of the first treatment could survive treatment and hatch a live head louse after the completion of a course of treatment [Lebwohl et al, 2007]. The average time from lay to hatch is 7 days, but longer intervals of up to 12 days between lay and hatch have been observed in laboratory studies.
  • Reinfestation is also a common cause of perceived treatment failure [PHMEG, 2008].

Can children with head lice attend school?

  • Children who are being treated for head lice can still attend school.
Basis for recommendation

The recommendation that children with head lice should continue to attend school is based on expert opinion [HPA, 2008; PHMEG, 2008].

  • Children discovered to have head lice will generally have had them for several weeks (many people have head lice without itch), so keeping children away from school is unlikely to reduce transmission.
  • Letters notifying other parents of cases have not been found to prevent the spread of head lice, but can provoke anxiety and itching.

Can head lice infestation be prevented?

  • It is not possible to prevent head lice infestation.
    • Regular detection combing (for example weekly) is the best way to identify any new head lice infestation quickly.
  • Whole-school 'Bug Busting® days' aim to educate children and their parents about the behaviour of head lice and how to detect and remove them. For more information, see the Community Hygiene Concern website www.chc.org.
  • The following are not recommended for preventing head lice transmission:
    • Products marketed as head lice repellents.
    • Repeated use of head lice treatments in the absence of lice.
    • Measures beyond normal personal hygiene, housekeeping, and laundry.
Basis for recommendation

Regular detection combing

  • The recommendation that detection combing is the best way to identify a head lice infestation quickly is based on expert opinion [Ibarra, 1998; PHMEG, 2008].

Bug Busting® days

  • A pilot scheme within one primary care trust using the Bug Busting® kit as first-line treatment, combined with participation in national Bug Busting® days in 62 local primary schools, reported a 24% decrease (£2300) in spending on prescriptions for head lice treatments during the financial year of the pilot scheme, compared with the previous year [Ibarra et al, 2007].

Prevention of infestation

  • CKS found no evidence that products marketed as head lice repellents are effective. There is concern that prophylactic use of insecticidal treatments puts individuals at greater risk of toxic effects than if head lice treatments are used appropriately, only when a live louse has been found.
  • There is no evidence that head lice treatments used prophylactically are effective, and there is concern that prophylactic use of insecticidal treatments could increase the risk of toxic effects. They should only be used if a live louse is found [PHMEG, 2008].
  • There is no evidence that measures beyond normal personal hygiene, housekeeping, and laundry can prevent reinfestation [Ibarra, 1998].

Prescriptions

For information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://emc.medicines.org.uk), or the British National Formulary (BNF) (www.bnf.org).

Dimeticone lotion (Hedrin®)

Age from 1 month to 1 year 11 months
Dimeticone 4% lotion: 2 applications 7 days apart
Dimeticone 4% lotion
Apply to dry hair and scalp. Spread the liquid evenly from roots to tips. Leave to dry naturally. Wash off after 8 hours. Repeat after 7 days.
Supply 50 ml.
Age: from 1 month to 1 year 11 months
NHS cost: £2.98
OTC cost: £4.99
Licensed use: yes
Patient information: Apply sufficient lotion evenly over dry hair ensuring that the scalp is fully covered. Spread the lotion evenly from roots to tips. Allow the hair to dry naturally, and keep away from naked flames or cigarettes whilst treatment is on the hair. Leave on the hair for 8 hours or overnight. Then wash hair. Comb with a detection comb while wet to remove dead lice. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated at the same time to prevent reinfestation.
Age from 2 years onwards
Dimeticone 4% lotion: 2 applications 7 days apart
Dimeticone 4% lotion
Apply to dry hair and scalp. Spread the liquid evenly from roots to tips. Leave to dry naturally. Wash off after 8 hours. Repeat after 7 days.
Supply 100 ml.
Age: from 2 years onwards
NHS cost: £5.96
OTC cost: £9.98
Licensed use: yes
Patient information: Apply sufficient lotion evenly over dry hair ensuring that the scalp is fully covered. Spread the lotion evenly from roots to tips. Allow the hair to dry naturally, and keep away from naked flames or cigarettes whilst treatment is on the hair. Leave on the hair for 8 hours or overnight. Then wash hair. Comb with a detection comb while wet to remove dead lice. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated at the same time to prevent reinfestation.

Head lice: wet combing

Age from 1 month onwards
Bug Buster® kit
Bug Buster kit
Use as directed in Additional Information.
Supply 1 kit.
Age: from 1 month onwards
NHS cost: £4.55
OTC cost: £8.05
Licensed use: no - misc item available on the NHS
Patient information: Wash hair with usual shampoo, rinse, and apply ordinary hair conditioner generously. Untangle and straighten hair with the wide-tooth comb. Pass a Bug Buster® comb from roots to tips, working over the head section by section. Lice lifted out will be visible in the foam on the comb. Clear the comb of lice between strokes by wiping the comb both sides on paper tissue, or rinsing. Comb each section until no more lice are found. The time required to cover the whole head ranges from 5 minutes for short, straight hair, to 30 minutes for long, frizzy hair. Rinse off conditioner and comb again with the wide-tooth comb, followed by the Bug Buster® comb, and then the Nit Buster® comb. Repeat 3 times at half weekly intervals (a total of 4 sessions over 2 weeks). If any full-grown lice are found at sessions 2, 3, or 4, continue half weekly sessions until no full-grown lice are found at 3 consecutive wet combing sessions. All infested contacts must be treated to prevent reinfestation.

Head lice: IPM/C (Full Marks solution)

Age from 2 years onwards
Isopropyl myristate and cyclomethicone: 2 applications 7 days apart
Cyclomethicone 50% / Isopropyl myristate 50% solution
Apply to dry hair and scalp. Leave on for 10 minutes. After 10 minutes, comb out dead lice with the detection comb provided. Wash out using shampoo when combing completed. Repeat after 7 days.
Supply 100 ml.
Age: from 2 years onwards
NHS cost: £3.42
OTC cost: £6.23
Licensed use: no - misc item available on the NHS
Black triangle
Patient information: Apply to dry hair so that the scalp and roots of the hair are saturated. Leave on the hair for 10 minutes. After 10 minutes, comb through the hair with an ordinary comb to remove tangles. Then, use the detection comb provided in the pack to remove dead lice. To ensure a thorough job, divide the hair into four quarters and comb each separately. The divide the first quarter into smaller sections to make combing easier. Place the teeth of the comb as close as you can to the scalp and comb downward away from the head to the tips of the hair. After each stroke, rinse out the comb to remove any hair and lice and wipe with a tissue. Once the whole head has been combed, wash out the product using ordinary shampoo. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated at the same time to prevent reinfestation.

Head lice: CAY spray

Age from 2 years onwards
Coconut, anise, and ylang ylang spray: 2 applications 7 days apart
Lyclear SprayAway spray
Apply to dry hair and scalp. Leave on for 15 minutes. After 15 minutes wash out using shampoo. Then comb out dead lice with the detection comb provided. Repeat after 7 days.
Supply 60 ml.
Age: from 2 years onwards
NHS cost: £6.54
OTC cost: £10.99
Licensed use: no - misc item available on the NHS
Patient information: Spray all over dry hair so that the scalp and roots of the hair are wetted. Thoroughly massage the spray into the hair and scalp for a minute to ensure that it is fully wetted. Leave on the hair for at least 15 minutes. After 15 minutes, wash the hair using ordinary shampoo and untangle using an ordinary comb. Then comb through the hair with the detection comb provided in the pack to remove lice. To ensure a thorough job, divide the hair into four quarters and comb each separately. Then divide the first quarter into smaller sections to make it easier to comb. Place the teeth of the comb as close as you can to the scalp and comb downward away from the head to the tips of the hair. After each stroke, rinse out the comb to remove any hair and lice and wipe with a tissue. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated at the same time to prevent reinfestation.

Malathion aqueous liquid

Age from 1 month to 1 year 11 months
Malathion 0.5% aqueous liquid: 2 applications 7 days apart
Malathion 0.5% aqueous liquid
Apply to dry hair and scalp. Leave to dry naturally. Wash off after 12 hours. Repeat after 7 days.
Supply 50 ml.
Age: from 1 month to 1 year 11 months
NHS cost: £2.37
OTC cost: £4.15
Licensed use: yes
Patient information: Apply to dry hair so that the scalp and roots of the hair are saturated. Allow to dry naturally. Leave on the hair for 12 hours or overnight. Then wash hair. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated at the same time to prevent reinfestation.
Age from 2 years onwards
Malathion 0.5% aqueous liquid: 2 applications 7 days apart
Malathion 0.5% aqueous liquid
Apply to dry hair and scalp. Leave to dry naturally. Wash off after 12 hours. Repeat after 7 days.
Supply 100 ml.
Age: from 2 years onwards
NHS cost: £4.74
OTC cost: £8.30
Licensed use: yes
Patient information: Apply to dry hair so that the scalp and roots of the hair are saturated (one bottle is usually enough). Allow to dry naturally. Leave on the hair for 12 hours or overnight. Then wash hair. Repeat treatment after 7 days. Use detection combing 2-3 days after final treatment, and again 9-10 days after the final treatment to check that treatment has been successful. All infested contacts must be treated t the same time to prevent reinfestation.

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