Head lice: myths and facts on the annoying little critters

The Stanford Freeholder
By DR. PAUL ROUMELIOTIS
September 18, 2008

Head lice infestation (pediculosis), one of the most common contagious childhood diseases, is caused by tiny insects found almost exclusively on the human scalp.

Every year, head lice infest millions of children in North America.

Children are especially susceptible because of their close contact in day cares and schools.

It is not surprising then, that the highest rate of infection occurs in September and October, as they return to school.

Although head lice infestation is not a serious disease, it is considered a nuisance by many and indeed can render a person uncomfortable.

What do head lice look like?

Head lice are grayish in color, and are barely visible to the naked eye.

Identifying lice can be difficult as they move very rapidly upon six legs.

Lice require warmth and humidity to survive, and so tend to be most concentrated around the back of the host's head and behind the ears.

A single female may lay up to 150 eggs, or "nits", during her lifetime. Nits are silvery-white in colour, oval in shape, and may look to the naked eye like tiny grains of sand cemented to the hair shaft.

Nits are smaller than adult lice, but are generally easier to identify because they're more numerous and don't move. Seven to nine days after being laid, the nits hatch and give birth to young lice that then start their own life cycle.

THE FACTS

There are a lot of misconceptions about head lice so I want to tell you about some common myths and the real facts:

Myth:The presence of lice is a sign of poor personal hygiene.

Fact:Actually, head lice seem to prefer a clean scalp; and otherwise show no particular preference for a human host's sex, race, age or socio-economic status.

Myth:Only children are susceptible.

Fact:Lice show no preference for children over adults. However, infestation is more common among children between three and 10 years because of their tendency to be in close contact with others, especially at school.

Myth:Long hair encourages infestation.

Fact:Since head lice are only interested in the immediate area of the scalp, cutting the hair will not prevent nor cure the infestation.

Myth:Lice can be contracted from plants, animals and pets.

Fact:Humans are the only hosts head lice survive on. Head lice cannot live on animals, pets or plants.

Myth:Lice can jump and fly from one person to another.

Fact:Head lice have no wings, they can only crawl -so transmission comes only from direct contact with other infested people or their belongings.

Indirect transmission can occur through sharing personal articles that come in contact with the scalp, such as hats, scarves, hair accessories, headgear, headphones, etc.

Lice infestation treatment includes the following three aspects:

* An appropriate shampoo rinse or cream used as directed.

* Combing through the hair to remove nits and lice after treatment.

* Disinfecting items that may have come in contact with the infested child's head.

Dr. Paul Roumeliotis is the Medical Officer of Health(A) for the Eastern Ontario Health Unit and Assistant Professor of Pediatrics, McGill University.

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