Most lice feed on blood several times a day, and they can survive up to 2 days off the scalp.
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 are usually spread from child to child when sharing clothing, hats, scarves, combs, brushes, hair trims or helmets that have strands of hair with nits. Lice can also be passed when playing contact sports. People of all ages and races can get lice, but they are less common in African American children.
Adults are not immune to head lice. In fact, if you have any close contact with children or even parents of children you can be at risk of catching them if they have them. Lice transfer primarily through head to head contact, so you would have to get close to the other person.
Head lice keep recurring when eggs are missed and left in the hair. Those missed eggs then hatch and you find head lice again. Removing all the eggs is key to stopping head lie recurring. The eggs are tiny and glued firmly onto the hair.
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.
Avoid head-to-head (hair-to-hair) contact during play and other activities at home, school, and elsewhere (sports activities, playground, slumber parties, camp). Do not share clothing such as hats, scarves, coats, sports uniforms, hair ribbons, or barrettes. Do not share combs, brushes, or towels.
Anyone can get head lice. They are not a sign of being dirty. Most people don't know they are infested until they see the nits or lice. They are found throughout the world, most commonly on children.
A preventative shampoo and spray can break the life cycle. A shampoo that kills lice before they can lay eggs is critical for closing the “bridge” from one head to another.
Head lice have difficulty gripping onto coily hair. As a result, Black people with coily hair and others with this hair type may be less susceptible to head lice. Head lice are small insects that live in human hair.
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. Life cycle image and information courtesy of DPDx.
The peak season for lice infestation is August through October and again in January. Head lice are tiny parasitic insects that feed on human blood. Lice come in three forms: nits (eggs), nymphs (baby lice), and adults. Nits are white or yellowish-brown and about the size of a poppy seed.
Head lice can affect anyone, and are most common in the 3-11 year old age group. Head lice are annoying and may cause itching, but they do not cause disease.
Permethrin lotion 1% is approved by the FDA for the treatment of head lice. Permethrin is safe and effective when used as directed. Permethrin kills live lice but not unhatched eggs.
Head lice eggs (nits) cannot hatch and usually die within a week if they do not remain under ideal conditions of heat and humidity similar to those found close to the human scalp.
Stage 1: Nit
Nits are another name for head lice eggs. They are less than 1mm in size: about the size of a knot in a thread. Many people misidentify nits as dandruff or hair residue. They are yellowish or tan in colour and can easily blend in with the hair colour of their host.
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.
Shaving the head does not cure lice. The itching should go away within a few days, but the medicated treatment will need to be repeated in 5 to 7 days to kill any new lice that may have hatched since the first treatment.
Common signs and symptoms of lice include: Intense itching on the scalp, body or in the genital area. A tickling feeling from movement of hair. The presence of lice on your scalp, body, clothing, or pubic or other body hair.
Lice and nits can live on pillows and sheets. Lice glue their eggs to the hair strands of their host. However, if a piece of hair with an egg falls out while the lice host is sleeping, an egg could end up on pillows or sheets.
Coconut, tea tree oil, lavender, eucalyptus, rosemary, lemon grass, and peppermint are scents popularly believed to repel lice. Using any coconut scented shampoo and conditioner is an easy way to increase your defense. At 1% concentration, tea tree oil killed 100% of head lice after 30 minutes.