Head lice are whitish to grey-brown in colour, and smaller than the size of a pinhead when first hatched. When fully grown they're about the size of a sesame seed. They can be a nuisance but they pose no threat to our health. Our thanks to NHS Choices for the use of the information below.
There are a significant number of myths and misunderstandings about head lice.
Prevalence: Head lice are a common problem, particularly in schoolchildren aged four to 11. It is estimated that at any one time 5% of the school population are living with an infestation but that's not to say adults are immune from them, recent research suggests there has been a rise in the number of reported cases in adults.
Life cycle of head lice: A female head louse lays eggs by cementing them to hairs (often close to the root), where they're kept warm by the scalp. The eggs are pinhead-size and difficult to see.
After seven to 10 days, the baby lice hatch and the empty eggshells remain glued in place. These remains are known as nits. Nits are white and become more noticeable as the hair grows and carries them away from the scalp.
Head lice feed by biting the scalp and feeding on blood. They take nine to 10 days to become fully grown. Head lice normally only crawl from head to head when they're adults or nearly mature juveniles.
A female head louse may start to lay eggs from nine days after she's hatched. Therefore, to break the cycle and stop them spreading, they need to be removed within nine days of hatching.
Detection: The only thing that can tell you if lice are present is to regularly contact trace a child with a special fine-toothed head lice comb with a tooth spacing of 0.2-0.3mm. If you find a living moving louse using this method -not an empty egg case, known as a nit - it is then important to do a little detective work and ensure that both the individual with the head lioe infestation and all those that have been in head to head contact with them are traced, combed and if necessary, treated, adults included.
Treatment: There are a range of approved insecticidal sprays and lotions for treating head lice. The best person to talk to about head lice infestations is your pharmacist. Various "natural" remedies are vigorously marketed on the internet but experts believe there’s little or no scientific basis for their claims of efficacy. Manual & mechanical removal of live lice and nits using conditioner to ‘wet’ the hair followed by laborously combing out the head lice with a fine tooth comb is the only 'alternative' detection and treatment method with any evidence to back up its efficacy. Here in the UK this method has been termed as ‘Bug Busting’ and popularised by the charity Community Hygiene Concern (www.chc.org/bugbusting)
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