Head lice are small insects around the size of a sesame seed that live on the human scalp. They cannot jump, fly or swim but are spread when people have their heads close together or by sharing combs, brushes and hats. The female lice lay eggs (nits) close to the scalp and these are glued firmly to each hair. After hatching, lice mature over 9-12 days to adulthood when they can reproduce.
An itchy scalp is due to sensitivity to the lice saliva but not all people will experience this, and some will feel itchiness after successful treatment. When looking for an infection, check for nits behind the ears and along the hairline at the back of the neck. Actually seeing live lice is tricky, but combing the hair with a fine-toothed comb can dislodge them.
If nits are found, check how far from the scalp they are. It is generally thought that eggs found further than 1cm from the scalp are likely to be hatched or non-viable and can remain on the hair for up to a year, if not successfully combed out. However, if the eggs are within 1cm of the scalp or live lice are found, other household members should be checked and affected people treated.
Dimethicone 4% lotion is available and subsidised through your doctor or pharmacist, for eligible people. It is effective with few side effects. Lice are unlikely to develop resistance to dimethicone lotion as it is not an insecticide, killing by suffocation instead. To treat, apply to dry hair, covering the full length of hair and all over. Comb with an ordinary comb to distribute. Leave to dry naturally and wait 8+ hours before washing the hair with the usual shampoo. Use a fine-toothed comb to remove remaining eggs, applying conditioner or water to the hair to loosen them. Repeat in 7-days to treat any lice that hatch from surviving eggs.
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