01.The lice lowdown
- Herbal treatments are increasingly popular, but unlike insecticidal products, most haven’t been clinically tested or independently assessed for effectiveness or safety.
- It’s important to use treatments as directed. Misusing products could contribute to lice resistance and adverse reactions.
- The comb and conditioner technique is an effective way to detect and remove head lice and nits (the eggs), but it’s time-consuming.
Please note: this information was current as of August 2007 but is still a useful guide today.
There are two types of treatment used to kill head lice and some eggs, based on their active ingredients:
Insecticides: Organophosphates (such as maldison or malathion), pyrethrins and synthetic pyrethroids (such as permethrin and bioallethrin). See Insecticide treatments for details.
Herbal: Various combinations of essential oils (commonly tea tree, melaleuca; eucalyptus; and lavender oils) and herbal extracts, with or without natural (as opposed to synthetic) pyrethrins, such as pyrethrum. See Herbal treatments for details.
Are lice resistant to treatment?
Tenacious parasites are becoming increasingly resistant to conventional insecticide treatments.
Resistance to the major insecticides used in Australia — malathion and permethrin — has developed in many other parts of the world. Research is not conclusive here, but resistance to malathion has already been reported in parts of Tasmania and Queensland and it’s likely that resistance to commonly used ingredients will become more widespread.
This increase in resistance, combined with apprehension about using insecticides on children, might explain why parents are increasingly choosing to ‘go natural’ and why CHOICE found twice as many herbal treatments as when we last reviewed head lice treatments in 2001.
Generally speaking, treatments in lotion form seem to be more effective than corresponding shampoos. Effectiveness can also vary as a result of:
- differences in formulation (concentration of active ingredient)
- how they’re applied (to dry versus wet hair)
- how long they’re left on.
See How to treat lice for a guide to effective treatment.
Lice lowdown: 10 interesting facts
- Head lice are small bloodsucking insects, about 2 to 3mm long. Their colour varies from whitish-brown to reddish-brown.
- Lice are wingless and can’t jump, but they can crawl and swing through the hair very quickly.
- People get lice from direct hair-to-hair contact with another person who has them.
- Having clean hair doesn’t protect you against lice –– they feed on blood from your scalp, not dirt, so it makes no difference if your hair’s dirty or clean.
- Lice live in the hair and move to the scalp to feed. They can live for up to 35 days.
- After mating, a female louse lays between three and eight eggs per day.
- Lice eggs (nits) are oval and about the size of a pinhead. Eggs are laid close to the scalp and are ‘cemented’ to the hair shaft.
- Eggs hatch about seven days after they’re laid. Young lice are called nymphs until they develop into adults 10 days later.
- Eggs and adult lice can only survive one to two days without the right temperature, humidity and food (your blood).
- Any egg found more than 10 to 15 mm from the scalp has either hatched or is dead.