London, June 5 (Reuters): They’re annoying and persistent and end up in the itchy scalps of countless schoolchildren every year, but head lice are essentially harmless and chemical treatments normally kill them, researchers said today.
Despite their frequency, confusion and misconceptions surround the sesame-seed size, six-legged parasites that grasp hair strands and feed on human blood.
“It stems from a fundamental lack of knowledge,” said Ian Burgess, the director of Insect Research and Development Ltd, a private consultancy firm in Cambridge, England.
There is also an emotional element involved because many people are reluctant to deal with creepy insects. “The idea of creepy-crawlies on your body is repugnant,” Burgess added.
One of the leading misconceptions about head lice is that it is possible to pick them up from inanimate objects. “This is a parasite that requires frequent blood meals,” said Burgess.
Head lice are spread by head-to-head contact, usually by people who know each other well. Lice seen on chairs, pillows or hats are dead and cannot infect anyone so it is pointless to spray things like sheets or furniture.
Although most common in children, adults can also get lice, which attach their eggs to hair shafts and lay five to six a day. The bugs are usually found at the back of the neck and behind the ears and are probably more common in girls, who are more likely to have close contact during play.
Cutting hair, or tying it back, does nothing to help get rid of lice, Beth Nash, a physician and editor said in a review in the British Medical Journal.
She also warned that hatched eggshells, or nits, may be confused with dandruff and said school policies, such as banning children with nits, are ineffective because fewer than 20 percent of children with nits will develop an infestation within 14 days.
“Head lice are harmless. If detached from their host they are vulnerable and effectively dead,” she said.
A variety of products are available to deal with lice, including chemical lotions, creams and shampoos.
The director said: “We need to improve education for professionals and the public so that whatever we do have to treat them is used efficiently and with the least exposure and risk to the public.”