Children can have a few
If you think you have lice, call your doctor. Your doctor can recommend a medicated shampoo, cream rinse, or lotion to kill the lice. These may be over-the-counter (OTC) or prescription treatments. It all depends on what your doctor thinks will work best for you.
Typically, 10–15 head lice are found. The number of lice often depends on personal hygiene, for example, how often the person bathes, shampoos, or changes and washes his/her clothing.
A person gets head lice because the insects crawl from person to person by direct contact or by sharing items — including combs, brushes and hats — with another person who has head lice. Poor hygiene doesn't cause head lice.
An adult female lice (also known as a louse) lays up to eight eggs daily and can live up to 30 days on a person's head. Throughout her lifetime, she can lay between 100 and 150 eggs. As more eggs (nits) are laid and become adults, the number of eggs multiplies.
Yet, the pesky mites keep coming back. There are two reasons for a recurrent lice infestation: The lice treatment you used didn't work. You or someone in your family came in contact with lice again.
Lice and nits can't survive the high heat. It's true that lice and nits can't survive temperatures above 113°F (45°C). This makes them susceptible to any heat source, such as a hairdryer or the plates of a hair straightener.
Can someone have nits but no lice? It may be possible to have nits but no lice. If a person cannot find any nymphs or adult lice in the scalp and the nits are more than a quarter of an inch from the scalp, these may be dead and from an old infestation. However, the lice could be in hiding.
Washing, soaking, or drying items at a temperature greater than 130°F can kill both head lice and nits. Dry cleaning also kills head lice and nits. Only items that have been in contact with the head of the infested person in the 48 hours before treatment should be considered for cleaning.
Lifespan of Lice
Off the scalp, nits (eggs) can't survive over 2 weeks. Adult lice survive 3 weeks on the scalp or 24 hours off the scalp.
Head lice survive less than 1–2 days if they fall off a person and cannot feed; nits cannot hatch and usually die within a week if they are not kept at the same temperature as that found close to the human scalp.
An infestation with lice is called pediculosis. In a normal healthy child, an infestation usually involves less than 10 live lice (7). Infestations may be asymptomatic. Itching may occur if the individual becomes sensitized to antigenic components of louse saliva that is injected as the louse feeds (7).
Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood several times daily. Without blood meals, the louse will die within 1 to 2 days off the host.
You Have to Treat Them
Head lice will not go away on their own. If you think your child has an infestation, there are several steps you should take right away. Call your doctor to confirm the diagnosis. Notify your child's day care or school so other students can be checked.
Hair dye may kill lice as it contains chemicals such as ammonia and hydrogen peroxide, which lice may be sensitive to. However, it is not likely that hair dye can kill nits, which will return as lice once hatched.
Heat Method:
There are recent studies that show that treatment of lice with heat can be quite effective in killing head lice. Products such as Lousebuster are very effective but even a home hairdryer can successfully treat lice.
Not everyone feels lice moving around on their scalp, but some people do. Dr. Garcia says that most of her patients say they “don't feel anything,” but others may get a creepy, tickling sensation as lice move around their head.
Nits often appear yellow or white although live nits sometimes appear to be the same color as the hair of the infested person. Nits are often confused with dandruff, scabs, or hair spray droplets. Head lice nits usually take about 8–9 days to hatch.
An untreated infestation can severely affect your health. Your scalp will itch due to the lice feeding off of the blood in your scalp. This can also lead to lice bites on your neck.
Hairspray makes it harder for the louse to grab hold. The smell of hairspray and the use of solvents (sad but true) in them can also deter creepy crawlies from finding their way in.
Do not use a conditioner. It can keep the lice medicine from working. Rinse well with warm water and towel dry. Do not use the towel again until it has been laundered.