Head Lice

The children have gone back to school but apart from knowledge and skills, what else might come home with your child? Unfortunately, nits or head lice.

Head lice are small grey-brown coloured insects that have an affinity for hair, particularly in children aged four to 11 years old. However, older and younger people can also get infected. Other signs of head lice include nits (which are the head lice’s yellowish egg shells) and lice faeces (black specks) in the scalp and hair. 
 

Risk Factors

• Female 
• Number of children in family 
• Sharing beds, clothing and hair brushes.

The infection is spread by head-to-head contact and generally occurs when children play together, or when they come into close contact with each other. This allows the insect to move from one head to another.
 

Clinical Features

Head lice usually cause an itch and irritation in the scalp. This can take several weeks to develop after the initial infestation.

• Predominantly lice are found at the nape of the neck and the skin behind the ears.
• Nits are generally easy to see after the eggs have hatched, as adherent white grains on the hair shaft.
• Red-brown spots on the skin are due to excreted digested blood.

Occasionally the eyelashes can become infested, although this is more frequently due to a different insect, the pubic louse 

Scratching can cause crusting and scale on the scalp. Hair pulling can lead to small areas of hair loss.

Not all people with head lice get an itchy scalp when they are infected. The itch associated with head lice is from sensitivity to the saliva of the head lice.
 

Treatment

Treatment of head lice usually consists of at least 2 applications of an insecticide and/or physical methods. 

• Treat all members of the family at the same time. Inform the daycare or school.
• The second application of insecticide is required 7–10 days after the first one because the eggs may survive, allowing new louse nymphs to hatch out.
• Physical methods are required to remove the nits, as simple washing is not effective.
   

Suffocating Agents

• Dimethicone 4% - Lice are unlikely to develop resistance due to mechanism of action. Cure rates are reported to be 69–92% after two applications one week apart.
   

Chemical Insecticides 

• Malathion - But resistance has been reported and cure rates are reported to be as low as 33%

Lotions, liquids or cream are preferred to shampoo (which is too weak to be reliable). They are applied directly to the scalp. It is important to follow the manufacturer’s advice on how long to use it and how often to repeat it due to potential toxicity.
 

Physical Methods

Physical methods of removing nits and lice are used  with insecticide treatments and may be required daily for several weeks.

• Nit combs used in wet hair are the most effective way of physically removing the lice and nits. Metal combs are best for thick hair, and plastic is kinder on fine or long hair.
• Apply a conditioner to the hair.
• Work through the scalp in sections
• Comb down the hair shaft towards the scalp

Expect nit removal to take at least half an hour. Repeat daily until no lice are found on 3 consecutive occasions.
 

Other Methods

• Shaving the head or cutting the hair very short is effective, but rarely necessary.
• Daily 30-minute exposure to hot air dryer over a period of one month destroys live eggs.
• Treatments using natural oils may be as effective as the chemical treatments that have been approved for use in head lice.
   

Your local community pharmacist can help you with advice about products to treat head lice and advise you about prevention of this troublesome condition.