What are head lice?

Head lice are tiny blood-sucking insects that spread through casual contact with another person who has them. The lice are most commonly found on the scalp, but can also infest eyelashes and eyebrows.

The lice lay eggs on the hair of the head. These eggs, called nits, are yellow or white and can be seen as the hair grows out. After hatching, the shell of the eggs stay attached to the hair. Lice range in size from 2mm to 4mm. They do not jump or fly and can not be passed on through pets. Contact with the hair of the infected person is the only way to catch head lice. Uncommonly, they can also be spread by common use of hairbrushes, combs, hats or pillowcases. Having head lice does not mean you are dirty and there are no serious health problems associated with them. They are very common in primary school children, but anyone can get head lice.

Signs and symptoms

Itchy skin on the scalp, neck, or around the ears is the main symptom of head lice. Itching is caused by the saliva from lice entering the skin during feeding. The lice are most active at night-time, so symptoms can often disrupt sleep. Not all people experience symptoms.

Head lice.Head lice are commonly found on the scalp. 

Methods for diagnosis

Examination of the scalp can reveal head lice or nits. A doctor can use a special lamp that makes nits glow pale blue. Nits are usually laid within 1.5cm of the scalp.

Types of treatment

Wet combing

Combing the hair is the most effective way of eradicating lice. Cover the entire head with a white conditioner and, using a fine-toothed comb, comb the hair from root to tip. After each stroke, wipe the comb clean onto a tissue or paper towel. Continue the combing until there is no conditioner left on the hair. Then, comb conditioner through the hair every second day until no live lice are found for 10 days.

The combing method is as effective as chemical treatments, but is more time-consuming. The conditioner stuns the lice and its slippery consistency makes it easier to remove them.

Combing the hair is the most effective way of removing lice. 

Chemical treatments

Head lice can be treated with a range of lotions. If your child is over two years old, they can be treated with non-prescription insecticides such as permethrin, pyrethrum, malathion, benzyl alcohol, spinosad and topical ivermectin. It is important to carefully follow the instructions for these medications. Generally, it is necessary to repeat the treatment 10 days later, as lice will often have hatched from eggs within that time.

Rarely, oral ivermectin may be prescribed, when lice do not respond to topical treatment. Treatments that use kerosene or petroleum should not be used as they are toxic.


If one family member has head lice, you can prevent head lice from spreading or coming back by treating your entire family. Use hot water to wash and hot-dry all bedding, towels and clothing used in the two days prior to starting treatment, as head lice can not survive for more than 48 hours away from humans.

Schools have different policies about who needs to be informed when a child has head lice. Many schools have moved away from such 'naming' policies because of the shame some people wrongly associate with head lice. Remember, head lice are not a sign of dirtiness, so there is nothing to be ashamed of. It is agreed by experts that it is unnecessary to remove children with head lice from school, if they are appropriately treated at home.


  1. Head lice. Accessed 16 September 2014 from link here
  2. Head lice - Department of Health Victoria Australia. Accessed 16 September 2014 from link here