Communicable Diseases

Lice

Abstract:

Head lice are small parasitic insects that live on the scalp where they lay their eggs and feed on blood.
Head lice are spread most commonly by direct contact from head to head, or by sharing belongings.
Head lice are most common among schoolchildren.
Constant and vigorous itching and the presence of lice eggs are the most important symptoms of having head lice.
Insecticides or benzene derivatives cannot be used to treat lice.

Overview:

Head lice are small parasitic insects that live on the scalp where they lay their eggs and feed on blood. A head lice infestation can be highly contagious. The adult female louse lays seven to ten eggs per day near the scalp. Head lice cannot jump or fly, but they can crawl, and they do not carry bacterial or viral infectious diseases. A head lice infestation isn't a sign of poor personal hygiene. While anyone can contract lice, most often they affect children in schools, who then transfer the infestation to their parents, health care providers, etc.

Transmission:

Direct head-to-head (hair-to-hair) contact with an already infected person
Sharing tools such as hairbrushes, towels, blankets, hats, and others
Home pets (e.g. dogs and cats) do not play a role in spreading head lice.

Symptoms:

The patient may not experience any symptoms at the beginning of a lice infestation because it may take some time for the lice to reach the scalp and the itching sensation to start.

Lice eggs (nits) on hair shafts
A tickling sensation in the scalp
The sensation of something crawling on the scalp
Frequent and intense itching of the scalp
Scalp irritation that leads to sleeping difficulties
Swelling in the lymph nodes found at the back of the head
Pink eye (conjunctivitis)

Not all scalp itchiness is caused by head lice; it could be due to other reasons like dandruff, eczema, and others.

Complications:

It is possible to develop an infection due to persistent itching of the scalp.

Treatment:

The doctor may recommend a special shampoo, cream or lotion to kill the lice, so it is recommended to follow the treatment as instructed by the doctor in addition to using lice combs. Itchiness may not disappear immediately after treatment. A persistent itch without evidence of an infestation is not a reason to repeat the treatment.

Prevention:

The whole family must be checked for lice especially those sharing the same bed. It is recommended to start lice treatments for all the members of the family who contracted lice at the same time.
Children should be instructed not to share tools with other people (e.g. combs, hats, scarves, towels, helmets, etc).
Head-to-head contact should be avoided as much as possible in schools whether at the gym, the playground, or during sports, as well as while playing at home with other children.
Children should be instructed not to lie down on beddings, pillows, and carpets recently used by someone with lice.
Avoid inspecting children's hair in schools by using the same tools (such as rulers or pens) on multiple children to avoid head-to-head contact and prevent the spread of lice.

Head lice management guidelines:

Do not use a hairdryer on the patient’s head after using any lice treatments, as some of them may contain flammable ingredients.
Do not wash hair for 1 to 2 days after the lice treatment.
Do not use insecticides to get rid of lice.
Do not treat an infested person more three times with the same medication.
Do not use different head lice medications at the same time.
Do not use chemicals such as gasoline or kerosene on the hair.

FAQ: