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This summary has been developed for use by community pharmacists under our Guidelines for Pharmacy title and therefore only covers the information relevant to this setting. Areas covered include: treatment and management, advantages and disadvantages of treatment options, information and advice for those with the condition. Please refer to the full guideline for the complete set of recommendations.

Management

How should I manage a person with a confirmed head lice infestation?

  • If a live head louse is found, treat with one of the following:
    • A physical insecticide — these silicone or fatty acid ester-based products kill the lice by physically coating their surfaces and suffocating them, so resistance is unlikely to develop.
      • They include dimeticone 4% gel, lotion, or spray (Hedrin® Once or Lotion; Chemists’ Own® Head Lice Spray); dimeticone 92% spray (NYDA®); dimeticone > 95% lotion (Linicin® Lotion); isopropyl myristate and cyclomethicone solution (Full Marks Solution®); and isopropyl myristrate and isopropyl alcohol aerosol (Vamousse® Head Lice Treatment), all of which are available on the NHS.
    • A chemical or traditional insecticide — these poison the lice by chemical means. 
      • In the UK, the only chemical insecticide that is currently recommended is Malathion 0.5% aqueous liquid (Derbac-M®), but resistance has been reported.
    • Wet combing — this is the systematic combing of wet hair with a louse detection comb to remove head lice. 
      • The Bug Buster® kit is the only head lice removal (and detection) method that has been evaluated in randomized controlled trials, and it is available on the NHS. 
      • Other nit combs listed in the Drug Tariff include Nitty Gritty NitFree comb®, Nitcomb–S1®, and Nitcomb–M2®.
  • The choice of treatment will depend on the preference of the person and/or their parents/carers after considering the advantages and disadvantages of each treatment, what has been previously tried, and the cost of the treatment. Be aware that:
    • Wet combing or dimeticone 4% lotion is recommended first-line for pregnant or breastfeeding women, young children aged 6 months to 2 years, and people with asthma or eczema.
    • Shampoos are generally not recommended because they are diluted too much and have an insufficient contact time to kill eggs.
  • Supply enough treatment to complete a treatment course. 
    • In general, a small bottle of insecticide is sufficient for treating short or shoulder-length hair, but a larger bottle or two small bottles would be needed for longer, thicker hair.
    • The Bug Buster® kit is reusable by a whole family.
  • Advise the person with head lice and/or their parents/carers to read the instructions that come with the treatment to ensure that it is used safely and correctly. Highlight that:
    • All affected family members should be treated on the same day to avoid reinfection.
    • For insecticides:
      • Treatment should be applied to all areas of the scalp and to all of the hairs, from their roots to their tips. 
      • The product should be left on for the time recommended by the manufacturer, then washed off. This varies from 15 minutes (for example with Hedrin® Once Spray Gel and Vamousse®) to at least 8 hours (for example with Hedrin® Lotion and NYDA®). A contact time of 8–12 hours (or overnight) is recommended for lotions and liquids.
      • It is generally recommended that insecticides are applied twice, at least 7 days apart, in order to treat any lice hatching from eggs before they lay more eggs themselves. Some experts suggest that 2 applications may be insufficient and that 3 applications may be required to achieve a complete cure.
      • Inappropriate use can lead to treatment failure and may increase the risk of resistant lice. 
      • The hair should be kept away from naked flames, cigarettes, and other sources of ignition during treatment with dimeticone-containing products (though not flammable, dimeticone is not water based and will not prevent hair from burning). Care should be taken if the product is spilt as it may cause a slip hazard.
    • For wet combing:
      • The recommended regimen is four sessions spaced over 2 weeks (on days 1, 5, 9, and 13).
      • It takes about 10 minutes to complete the process on short hair, and 20–30 minutes for long, frizzy, or curly hair. Two combing procedures are recommended at each treatment session.
      • Detailed information on wet combing is provided in the Bug Buster® kit and is also available on the Community Hygiene Concern website (www.chc.org). 
  • Advise that after treatment, detection combing should be done to check that the treatment was successful. 
    • For insecticide treatments, opinions differ as to how this should be done. For example:
      • The UK Medicines Information (UKMi) Cymru Wales recommend that detection combing should be done 2 or 3 days after the second application of treatment and again after an interval of 7 days (that is, day 9 or 10 after completing a course of treatment). Treatment has been successful if no lice are found on both occasions.
      • Advice from Community Hygiene Concern (www.chc.org) is that regardless of the treatment used, detection combing should be done on days 5, 9, and 12/13 after the first application to avoid the risk of continuing infestation. Treatment has been successful if no lice are found on all occasions.
    • For wet combing, a fifth detection combing session should be done on day 17. Treatment has been successful if no lice are found on day 17.
    • Explain that the presence of louse eggs alone (whether hatched [nits] or unhatched) and/or itching do not indicate treatment failure.
  • Give additional information and advice, including on how to reduce the risk of reinfestation. See the section on Information and advice for more information.

Advantages and disadvantages of the different treatment options

Physical insecticides

  • Dimeticone 4% (Hedrin® Lotion, licensed medicinal product)

    • Advantages

      • Dimeticone has a well-established safety profile and is usually well tolerated [ABPI Medicines Compendium, 2014].
      • It can be used in pregnant and breastfeeding women and in children aged 6 months and older [ABPI Medicines Compendium, 2014].
      • The manufacturer states that Hedrin® products are suitable for people with asthma. 
      • Cure rates of 70% have been reported in clinical trials in the UK [Burgess et al, 2005Burgess et al, 2007].
      • It kills louse by creating a physical barrier around it, so resistance is unlikely to develop.
      • It is odourless.
    • Disadvantages

      • It has poor ovicidal activity (ability to kill the eggs as well as the live lice).
      • Minor adverse effects (including skin irritation) have been reported with dimeticone. A single case of hair loss has also been reported. 
  • Dimeticone 4% (Hedrin® Once [Liquid and Spray Gel], registered medical device)

    • Advantages

      • Dimeticone has a well-established safety profile and is usually well tolerated [ABPI Medicines Compendium, 2014].
      • The manufacturer states that Hedrin® products are suitable for people with asthma. 
      • Cure rates of 70% have been reported in clinical trials in the UK [Burgess, 2013]. 
      • It kills louse by creating a physical barrier around it, so resistance is unlikely to develop.
      • Has a faint perfume fragrance.
      • Has good ovicidal activity.
    • Disadvantages

      • The manufacturer states that Hedrin® Once can be used in pregnant and breastfeeding women and in children aged 6 months and older; however, there is a lack of safety data on its use in these groups. CKS recommends Hedrin® Lotion for use in pregnant and breastfeeding women and in children aged 6 months to 2 years, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].
      • Minor adverse effects (including skin irritation) have been reported with dimeticone. A single case of hair loss has also been reported. 
      • Eggs may not be adequately covered with gel during application to achieve complete kill. Spray gel may work better than liquid gel [Burgess, 2013].
  • Dimeticone 4% (Chemists’ Own® Head Lice Spray, registered medical device)

    • Advantages

      • Dimeticone has a well-established safety profile and is usually well tolerated [ABPI Medicines Compendium, 2014].
      • Dimeticone kills louse by creating a physical barrier around it, so resistance is unlikely to develop.
      • It is odourless.
    • Disadvantages

      • There are no published clinical trials for its use.
      • The manufacturer states that it can be used in pregnant and breastfeeding women and in children aged 6 months and older; however, there is a lack of safety data on their use in these groups. CKS recommends Hedrin® Lotion for use in pregnant and breastfeeding women and in children aged 6 months to 2 years, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].
      • Two 8-hour applications are needed.
  • Dimeticone 92% (NYDA®, registered medical device)

    • Advantages

      • Dimeticone has a well-established safety profile and is usually well tolerated.
      • Cure rates of 97% have been reported in one clinical trial in Brazil [Heukelbach et al, 2008].
      • Dimeticone kills louse by creating a physical barrier around it, so resistance is unlikely to develop.
      • It has good ovicidal activity.
    • Disadvantages

      • There is a lack of safety data on its use in pregnant or breastfeeding women and in children younger than 2 years of age. CKS recommends Hedrin® Lotion for use in these groups, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].

  • Dimeticone > 95% (Linicin® Lotion, registered medical device)

    • Advantages

      • It kills louse by creating a physical barrier around it, so resistance is unlikely to develop.
      • Dimeticone has a well-established safety profile and is usually well tolerated.
    • Disadvantages

      • The manufacturer states that Linicin® Lotion can be used in pregnant and breastfeeding women and in children aged 6 months and older; however, there is a lack of safety data on its use in these groups. CKS recommends Hedrin® Lotion for use in pregnant and breastfeeding women and in children aged 6 months to 2 years, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].
      • Compared with other treatments for head lice, there is very little UK experience with its use, and there are no published randomized controlled trials on its use.
  • Isopropyl myristate and cyclomethicone (IPM/C, Full Marks Solution®, registered medical device)

    • Advantages

      • IPM/C kills head lice by dissolving the wax coating on the louse exoskeleton, leading to uncontrollable dehydration and subsequent death, so resistance is unlikely to develop.
      • Cure rates of 52% and 82% have been reported in clinical trials in the UK [Kaul et al, 2007Burgess et al, 2008].
      • It is odourless.
      • Suitable for people with asthma.
    • Disadvantages

      • There is a lack of safety data on its use in pregnant or breastfeeding women or children younger than 2 years of age. CKS recommends Hedrin® Lotion for use in these groups, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].
      • There is a lack of trial data for use by people with skin conditions.
      • Skin irritation has been reported in clinical studies, but it is uncommon and usually mild.
      • Ovicidal activity is unknown.
  • Isopropyl myristate and isopropyl alcohol (Vamousse®, registered medical device)

    • Advantages

      • Largely physical action, so resistance is unlikely to develop.

    • Disadvantages

      • There is a lack of safety data on its use in pregnant or breastfeeding women or children younger than 2 years of age. CKS recommends Hedrin® Lotion for use in these groups, as it is licensed for use in these groups [ABPI Medicines Compendium, 2014].
      • There is a lack of trial data for use by people with skin conditions.
      • Contains alcohol so not recommended for people with asthma.
      • There are no published clinical trials on its use.

Traditional insecticides

  • Malathion 0.5% aqueous liquid (Derbac M®)

    • Advantages

      • A review of safety data on topical malathion concluded that there is no evidence of serious systemic adverse reactions associated with its use, although the manufacturers state that skin irritation can occur. 
      • Cure rates of 75% and 33% have been reported in clinical trials of two applications one week apart [Roberts et al, 2000Burgess et al, 2007]. 
      • Suitable for people of all ages and people with asthma or skin conditions, as it does not contain alcohol.
      • Can be used in pregnant and breastfeeding women if wet combing and dimeticone are ineffective, as it is a licensed product and the manufacturer states that there are no known effects in pregnancy and lactation [MHRA, 2015]. 
    • Disadvantages

      • Resistance to malathion has been reported [BNF 72, 2016].
      • Some parents are reluctant to expose their children to a traditional insecticide.
      • It has an unpleasant smell.
      • Skin irritation, hypersensitivity reactions (such as anaphylaxis, angioedema, and swollen eyes), and chemical burns have been reported with malathion products. 

Wet combing (for example using the Bug Buster® kit) 

  • Advantages 

    • No insecticides are used, so resistance is not an issue. 
    • No contraindications or precautions for its use. 
    • The method is inexpensive, and the Bug Buster® kits are reusable. 
    • Clinical trials report cure rates of 38% and 52% at 14/15 days [Roberts et al, 2000; Hill et al, 2005].
  • Disadvantages

    • The technique is time-consuming and labour intensive; this may be a drawback when treating young children or if several people are to be treated at the same time.
    • The method is ineffective if an unsuitable comb or incorrect method is used.

What information and advice should I offer?

  • Give general advice, including that:

    • Children who are being treated for head lice can still attend school.
    • There is no evidence that head lice have a preference for either clean or dirty hair.
    • There is no need to treat (wash at high temperature or fumigate) clothing or bedding that has been in contact with lice.
    • No treatment can guarantee success. However, a treatment has the best chance of success if it is performed correctly and if all affected household members are treated on the same day.
    • Essential oil-based treatments and herbal treatments are not recommended due to the lack of good-quality evidence on their safety and efficacy.
    • It is not possible to prevent head lice infestation. However, children of primary school age should be examined regularly (for example weekly) at home to identify infestation early.
    • The following measures are not recommended for preventing head lice transmission:
      • Products marketed as head lice repellents.
      • Repeated use of head lice treatments in the absence of live lice.
      • Measures beyond normal personal hygiene, house cleaning, and laundry.

© NICE 2016. NICE CKS on head lice. Available from: cks.nice.org.uk/head-lice. All rights reserved. Subject to Notice of rights.

NICE guidance is prepared for the National Health Service in England. All NICE guidance is subject to regular review and may be updated or withdrawn. NICE accepts no responsibility for the use of its content in this product/publication. 

Last updated: December 2016.