Ask the Chemist

What are Head Lice

Head lice can sometimes be difficult to treat due to a high re-infestation rate and their ability to develop immunity (resistance) to traditional insecticides contained in some medications.

Headlice
Ask one of trained team for the best line of treatment.

It is thought that head lice will not develop immunity to the newer silicone- and oil-based preparations because they have a physical rather than a chemical action on lice.


After a head lice infestation has been confirmed, you can treat the lice at home by wet comb using a head lice comb or medicated lotions (see below).


However, neither treatment method will protect against re-infestation if head-to-head contact is made with someone with head lice during the treatment period.



Wet combing method
The wet combing method involves removing the head lice by systematically combing the hair using a special fine-toothed comb with a spacing of less than 0.3mm. Your pharmacist can advise you on which combs are suitable.


No medicated products are necessary for wet combing. This can be beneficial because head lice are becoming more resistant to the insecticides that are commonly used to remove them.


However, the success of the wet combing method depends on adopting a painstaking approach that involves regular and thorough combing.


The wet combing method is described below.

  • Wash the hair as normal using an ordinary shampoo.
  • Apply conditioner liberally to wet hair (this makes the lice lose their grip on the hair).
  • Use a normal comb to run through the hair until the comb runs freely.
  • Switch to a special fine-toothed louse comb, and comb from the roots upwards, along the complete length of the hair.
  • After each stroke, check the comb for lice and wipe it clean. Work methodically over the whole head for at least 30 minutes.
  • Rinse the hair as normal.
  • Repeat the procedure on day 5, 9 and 13 to clear the young lice as they hatch, before they have time to reach maturity.

Medicated lotion or spray
Medicated lotion or spray is an alternative method for treating head lice. However, no medicated treatment is 100% effective. Your pharmacist will be able to recommend an over-the-counter lotion or spray.


Medicated treatments should only be used if a living (moving) head louse is found. Crème rinses and shampoos are not thought to be effective and are therefore not recommended.


Make sure that you have enough lotion to treat everyone in your family who is affected by head lice. Use enough to coat the scalp and the length of the hair during each application.


Follow the instructions that come with the medicated lotion or spray when applying it. Depending on the product you are using, the length of time that it needs to be left on the head can vary from 10 minutes to 8 hours.


The normal advice is to treat once, then repeat after seven days. Some medicated products also supply a comb for removing dead lice and eggs.


Traditional insecticides must not be used more than once a week for three weeks in a row. Some products carry a fire warning.


Some medicated products may be capable of killing eggs as well as lice, although there is no certainty of this. Check for baby lice hatching from eggs three to five days after you use a product, and again 10 to12 days afterwards.


A minimum of two applications of lotion are needed to kill the lice over the hatching period because the lotions do not always kill louse eggs.


If the lice appear to be unaffected by the product (some lice may have developed resistance to a particular insecticide) or if the problem persists, seek advice from your school nurse, health visitor, pharmacist or GP.


Cautions
Always seek advice from a healthcare professional before using medicated head lice lotions on the following groups:

  • young babies (under six months old)
  • pregnant women
  • people with asthma or allergies

Pregnant women are advised to use either wet combing or 4% dimeticone lotion, which is licensed for use in pregnancy and breastfeeding.


Always read the instructions carefully before using medicated head lice lotions.


There are many myths about headlice and treatments to view these see the link below
http://www.chc.org/homedir/mistakenadvice.cfm

Good Advice

  • Be extra vigilant for head lice if there have been frequent reports of head lice at your child's school.
  • Wash your child's hair with a regular shampoo and hair conditioner and then check your child's hair after you rinse and dry it, but while it is still damp. The hair conditioner can make it easier to comb through your child's hair.
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