Head Lice.

 

Definition:

Head lice is a term which describes the infestation of Pediculus capitis, which lives on, and among, the hair of the scalp and neck of humans. The head lice are tiny brown/ grey insects, they lay eggs which hatch after 7-10 days into a new louse. Sometimes, people may refer to head lice as nits- this is actually the term to describe the empty white eggshells which stick to the hair.

 

 

Causes:

Head lice are passed from head-to-head by contact between two people. Children frequently contact heads, whilst in the classroom or playing, which is why head lice are most common in those aged between four and eleven years of age. They will live in either clean or dirty hair.

 

 

Presentation:

The main obvious symptom is that patients will have an extremely itchy head. This itching is caused by an allergic reaction to the salvia of the head lice. It should also be possible to see the nits (white eggs) on the hair shaft- most commonly found at the nape of the neck and back of the ears.

 

Adult lice may also be seen upon examination, they are greyish-brown in colour and about the size of a sesame seed.

 

 

Differential Diagnosis:

Ensure that live lice have been found. The patient may complain of itching but this may be due to a skin condition such as eczema, or a persisting itch even after a successful treatment of head lice, the itch can last for several weeks after lice eradication.

 

Nits can be confused with dandruff or hairspray. Only nits will be difficult to brush out of the hair,

allowing identification.

 

 

Treatment:

Traditional pesticides can be used, these are chemicals that kill head lice and eggs. Permethrin

and malathion are available in the UK; two treatments should be applied 7 days apart to avoid

re-infestation. For example, malathion should be applied to the hair from root to tip, left for 12

hours or overnight and then washed out with shampoo.

 

Non- traditional pesticides can also be used, which contain products to kill head lice through a

physical action i.e. coating them- this means the head lice cannot become resistant to them. 2

treatments should be carried out 7 days apart. For example, Hedrin Lotion, which is left on the

hair for 8 hours or overnight, then washed out with shampoo. Hedrin should ideally be the choice

promoted to patients- it is more effective than tradition pesticides and there is no risk of

resistance.

 

The last method is wet combing, using a metal comb to brush the lice and nits out of the hair. The

hair should be washed with ordinary shampoo, then copious amounts of conditioner should be

applied and left in the hair. Starting at the nape of the neck, work through the hair in sections,

brushing from root to tip and checking the comb after each stroke for nits and lice. If any are seen

they should be wiped away before the next stroke. This technique needs to be repeated every 4

days for 2 weeks, and if any adult lice are found after the 1st session, 3 further sessions at 4 day

intervals will be needed until no lice are found.

 

 

Self Help Advice:

A child with lice does not need to be kept away from school.

 

All members of the household should be checked for head lice, and any with head lice treated simultaneously. Inform all close contacts when lice are found.

 

Examine children's hair regularly using a detection comb.

 

Check clothes and bedding for lice waste (black specks).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sample Question:

A woman visits your pharmacy to ask you to recommend something that she can buy for her 10-year-old daughter to treat head lice. The child has asthma but is otherwise well. Which of the following products would it be appropriate for you to recommend? You may select more than one answer if applicable.

 

a) Derbac-M liquid (malathion 0.5%)

b) Hedrin lotion (dimeticone)

c) Lyclear Creme Rinse (permethrin)

 

Answers to all sample questions can be found by following the link under the Test Yourself tab.