Head lice are small, wingless insects that live, breed and feed on the human scalp. The eggs are firmly attached to the hair fibres, within 1.5 cm of the scalp, and rely on warmth from the head to hatch. People catch head lice from direct head-to-head contact with another person who has head lice. This can happen when people play, cuddle or work closely together.
If your family has head lice, tell anyone who has had head-to-head contact with them, so that they can check and treat their family if needed. There is no need to treat the whole family, unless they also have head lice. Concentrate on treating the affected person’s head. There is no evidence to suggest that you need to clean the house or the classroom. The only linen that requires changing is the affected person’s pillowcase. Wash it in hot water or dry it in a clothes dryer set to warm or hot.
Itchiness may not disappear immediately after treatment. Persistent itch without evidence of persistent infection is not a reason to repeat the treatment. There are other reasons why your scalp might feel itchy.
Finding head lice
Head lice eggs are oval, and the size of a pinhead. They are firmly attached to the hair shaft and cannot be brushed off. Anyone can catch head lice.
Treatment for head lice
The two preferred treatment options available for initially treating head lice are the ‘conditioner and comb’ method, and the use of an insecticide.
Using insecticide products
If you use a lotion, apply the product to dry hair. For shampoo products, wet the hair, but use as little water as possible. Head lice live in the hair and go to the scalp to feed. Therefore, head lice products must be applied to all parts of the hair. Once the treatment has been done according to the instructions on the packet, comb through the hair again with the fine tooth head lice comb. This will help to remove the dead eggs and lice, and possibly any eggs still living.
Care should be taken when using head lice treatment products if you are pregnant or breastfeeding, or in children less than 12 months old.
All products can cause reactions. If you are unsure, check with your pharmacist or doctor. No topical insecticide treatment kills 100 per cent of the eggs, so treatment must involve two applications, seven days apart. (This kills the lice that hatched from the eggs that didn’t die the first time around.)
Insecticide resistance
Insecticide resistance is common, so you need to check that the lice you comb out are dead. If the insecticide has worked, the lice will be dead within 20 minutes. If the lice are not dead, the treatment has not worked and the lice are resistant to the product and all products containing the same active compound.
The active compounds in head lice products are pyrethrins, synthetic pyrethroids (permethrin), organophosphates (maldison or malathion), and herbal, with or without natural (non-chemical) pyrethrins.
If a product with one of these active compounds has not worked for you, you can try another or speak to your pharmacist or doctor.