Putting a stop to head lice

Published in Medicinewise Living

Date published: About this date

Children often catch head lice at school through close contact — but these harmless insects can spread to anyone, no matter how clean or short you keep your hair.

You can help control head lice by treating it appropriately and stopping its spread to others (see 5 tips to prevent the spread of head lice).

Have you found live lice?

Lice move fast and are hard to spot, so you may only notice their eggs (nits) on the hair or itching. But you must find live lice to confirm an infestation.

Itching is caused by an allergy to lice saliva, not bites, so it’s possible to have head lice without itching. Conversely, you may itch for days after an infestation has been cured. Eggs attached to the hair may be from a previous infestation, and you can’t tell whether they’re viable or dead just by looking at them.

Look for live lice by ‘wet combing’

Spread a generous amount of hair conditioner through wet hair, then comb sections of hair from root to tip using a fine-toothed comb. Lice and nits can be detected by wiping conditioner from the comb onto a paper towel or tissue. Work through the whole head of hair and repeat at least twice to ensure any live lice are found.

Treat only if you find live lice

Using a medicated head lice product or wet combing can cure an infestation, but no single treatment kills all eggs or is assured to work — choice comes down to personal preference, what’s worked before, and other factors like the child’s age.

Various shampoos, lotions and sprays containing an insecticide against head lice are available from pharmacies. Get advice when choosing a product: some can smell or irritate the skin, or may be easier to apply than others. Some people should not use certain head lice products without seeking advice from a doctor first. They include: children younger than 2 years; people with asthma or skin conditions; and pregnant or breastfeeding women.

Instead of using a head lice product, you can try daily wet combing with a hair conditioner: this needs to be continued for 10–14 days until lice and eggs are removed, but it does not kill them. Alternatively you can try killing lice with an electronic comb (also available from pharmacies).

Insecticide treatment must be repeated

Always follow instructions for using insecticides to ensure they work. Because insecticides have little effect on eggs, a second application 7–10 days later is necessary to kill lice that hatch after the first treatment.

Use wet combing with a hair conditioner the day after each application to check for live lice, and twice in between applications to help remove eggs.

Seek advice if head lice persist

Lice are becoming more resistant to conventional insecticides like maldison (the active ingredient in brands like HL 7) and permethrin (e.g. Quellada). If the treatment you choose is unsuccessful, you may need to try a different product or method.

Make sure you re-treat all affected contacts to prevent re-infestation. But be careful not to overuse insecticides: this may cause skin irritation and resistance within lice populations.

Head lice: 5 tips to prevent spread

  • Soak combs and brushes in hot water (at least 60°C) for 30 seconds.
  • Wash pillow cases in hot water or heat in clothes dryer for 15 minutes.
  • Don’t share hats, combs, brushes or other hair accessories.
  • Tie long hair back to reduce contact with an infected person.
  • Check household and other close contacts and treat at the same time.