Head lice are second only to the common cold as a contagious illness in school-aged children.
Head lice are wrongly believed by many to be a sign of poor hygiene. Head lice are benign, treatable and not responsible for the spread of any disease.
An adult head louse is only about 2-3 mm in size (about the size of a sesame seed).
A six-legged wingless insect, the louse clings to our hair and bites our scalps to feed on tiny amounts of our blood.
Female lice hatch and mature from babies into fertile adults in about 10½-13 ½ days.
They can lay up to 10 eggs a day and live for a total of three-four weeks.
Eggs usually hatch in 7-12 days. The eggs and the empty egg cases are often referred to as “nits.”
Children between 3-12 years of age are most commonly infected.
Head lice usually spread by head-to-head contact (they only crawl), but occasionally by contact with personal items (brushes, caps, etc.) or surfaces (pillowcases, sofa backs, etc.).
The itchiness most associated with lice happens when we become sensitive to their saliva. This can leave little red bumps on the scalp.
Occasionally scratching these bumps can infect them with bacteria, causing impetigo.
The best way to diagnose head lice is by finding live lice on the scalp.
Prevention of lice is difficult, but not sharing personal items is a good idea.
School screenings for lice have been shown to make little difference in their spread.
Treatment of head lice is usually initiated using over-the-counter 1% permethrin or pyrethrins that are applied to the scalp.
If these do not work (lice can become resistant to certain treatments), 0.5% malathion or 5% benzyl alcohol preparations are sometimes prescribed.
Re-treatment in order to destroy lice that have hatched out after the first treatment is usually recommended.
Friends and family of children should be checked for infection and treated if infected.
Persons sharing a bed with an infected individual should probably be treated.
Bedding should be hot washed, and contacted surfaces cleaned.
Unwashable items can be put in airtight plastic bags for two weeks.
The American Academy of Pediatrics recommends that otherwise healthy children with lice be allowed to remain in school.
The AAP also recommends that no-nit policies be abandoned.