Generally, if no live crawling insects are seen three weeks after the treatment, it's safe to assume that they are gone. Nits would have hatched by that time if they were alive. Nits and their shells may remain in the hair for some time but won't be viable.
After each treatment, checking the hair and combing with a nit comb to remove nits and lice every 2–3 days may decrease the chance of self–reinfestation. Continue to check for 2–3 weeks to be sure all lice and nits are gone.
Continue to check hair and use the nit comb to remove nits and lice every 2 to 3 days for 2 to 3 weeks. This process should be done for as long as nits and lice are still found on the head. Many lice medicines recommend a second treatment in 9 to 10 days.
One treatment with Nix kills all the lice. Nits (lice eggs) do not spread lice. Most treated nits (lice eggs) are dead after the first treatment with Nix. The others will be killed with the 2nd treatment.
The head lice may have become resistant to the treatment. If the treatment used does not kill the head lice, your health care provider and pharmacist can help you be sure the treatment was used correctly and may recommend a completely different product if they think the head lice are resistant to the first treatment.
After treatment, your skin may still itch for a week or more. This is because of your body's reaction to the lice. Follow-up care is a key part of your treatment and safety.
Head lice cannot live for long on pillows or sheets. It is possible for a live louse that has come off a person's head to crawl onto another human host who also puts their head on the same pillows or sheets.
The life cycle of the louse starts with a female laying her eggs, which are known as nits. Nits are minuscule, smaller than the head of a pin. They're hardy too, attaching on the hair shaft close to the scalp with a glue-like adhesive. This is what makes it so tough to get rid of head lice permanently.
Head lice sometimes go away on their own because there are not enough insects to maintain the infestation, or they may persist for an indefinite period without treatment. With proper treatment, the infestation usually goes away within about two weeks.
Children can have a few nits without actually having a case of head lice. Usually children have no more than 10 to 20 live lice. Good lighting is important when you are checking. Head lice move fast and are hard to see.
Spinosad (Natroba).
Spinosad is approved for adults and children age 6 months and older. It can be applied to dry hair and rinsed with warm water after 10 minutes. It kills lice and nits and usually doesn't need repeated treatment.
How many head lice are usually found on an infested person? 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.
It is not usually possible to get rid of lice in one day, as an infestation needs to be treated. However, there are treatments that can help get rid of lice and symptoms caused by lice more quickly. Lice infestations must first be treated by improving the hygiene of the infected person.
One method that people have attempted to use is a blow dryer or hair straightener, thinking the heat would dry up and kill any lice. This idea is heading in the right direction, and while desiccation can be used to kill lice, it's important to note that a regular hair dryer or straightener will not treat lice.
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.
Lice don't care if hair has been colored. As long as a louse can grab on to a hair strand, it can make its way to the head where its food supply (blood) is. Myth #6: Lice like dirty hair.
Lice are most often spread by head-to-head contact with another person who has lice, such as sleeping in the same bed. Although they do not survive long away from a human host, lice may also be spread by wearing another person's hat or clothing, or by using another person's comb, brush, or bedding.
Although louse bites are harmless, they cause irritation and itching must like most bug bites do. However, excessive scratching could worsen the bites and cause bacterial infections, which may cause additional pain and itching.
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.
Some people may not have symptoms, particularly with the first infestation or when the infestation is light. It may take 4-6 weeks for itching to appear the first time a person has head lice.
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).
Who is at risk for getting head lice? Head lice are found worldwide. In the United States, infestation with head lice is most common among pre-school children attending child care, elementary schoolchildren, and the household members of infested children.