Head lice are tiny parasitic insects that spread through direct head-to-head contact — they cannot jump or fly. First-line treatment is permethrin 1% shampoo (like Nix) applied to dry hair, left on for 10 minutes, rinsed, and repeated in exactly 9 days. Comb out dead lice and nits with a fine-toothed nit comb after each treatment. Call your pediatrician if two rounds of over-the-counter treatment have not worked — prescription options are available and highly effective.
Back to school comes with lots of fun things – a new backpack and lunch box, seeing old friends and making new ones, the start of Fall. Unfortunately, it also causes an increase in the amount of lice we see in our office. While harmless, these bugs are irritating for the whole family and can lead to absences from school and work. This school year, be armed with the knowledge of how to prevent and, if needed, treat these pesky uninvited guests.
What are lice?
Lice are tiny gray bugs that can infest the scalp. They are about the size of a sesame seed and move quickly so can be difficult to see. What you often do find are their white eggs, called nits, which firmly attached to hair shafts near the skin. Unlike dandruff or sand, nits cannot easily be shaken off the hair shaft. Most people who get lice complain of an itchy scalp. Lice do not carry diseases and will not make you feel sick.
Lice life cycle
Nits hatch into lice in about one week. They can survive off the scalp during that time which makes cleaning your house imperative when treating a lice infection in the family. Adult lice can live three weeks on the scalp and feed every few hours on tiny amounts of blood from the scalp. Off the scalp, adult lice cannot survive for more than one day without a blood meal.
Transmission
Nits cannot pass from person to person; only live lice can infect other people. Almost all transmission is from direct head-to-head contact. Since lice cannot jump or fly, it takes about 30 minutes of direct contact for a louse to crawl from one head to another. However, indirect transmission from hats, hairbrushes, headphones and other objects is possible though less common. Most transmission of lice happens at home, through sleepovers and bed sharing.
Treatment
Anti-lice shampoo (such as Nix which is over the counter) is the mainstay of treatment and requires two treatments so be sure to follow the package directions. Prescription anti-lice medication such as Sklice, is also available and requires only one application. Discuss with your doctor if this is a good choice for your family.
When using the anti-lice shampoo, first wash hair with a regular shampoo and towel dry. Do not use conditioner on the hair as it interferes with the lice treatment. Pour 2 ounces (one box of Nix if that’s what you are using) into damp hair. People with long hair may need to use two boxes. Work the cream into all the hair down to the roots and add a little warm water if needed to work up a lather. Leave the shampoo on for a full 10 minutes and then rinse the hair thoroughly with water and towel dry. Again, do not use conditioner. Do not shampoo the hair for 48 hours after application of anti-lice shampoo and avoid hair conditioner before treatment as well as for 2 weeks after.
Most importantly, most over the counter shampoos require that you repeat the entire process 9 days later to kill any nits that survived. Since nits hatch 6-9 days after being laid, the second treatment will ensure that lice that hatch from surviving nits are also killed.
Preventing Spread
Now that the hair is under control, it’s time to address the house. Vacuum your child’s room thoroughly as well as the rest of the house. Soak hairbrushes for 1 hour in a solution containing anti-lice shampoo. Wash bed sheets, blankets, pillowcases and any clothes worn in the past three days in hot water; water temperature of 130 degrees Fahrenheit kills lice and nits. For items that cannot be easily washed, such as hats or stuffed animals, place them in sealed plastic bags for 2 weeks to ensure that all nits and lice are dead. Remind family members not to share combs or hairbrushes to prevent passing lice in the future.
Most importantly
Don’t stress! Lice infection does not happen because of a lack of cleanliness – it just happens. If you follow the above steps, lice and their nits should be successfully killed. Children can return to school and daycare after treatment with an anti-lice shampoo. A child does not need to miss any school or childcare due to nits remaining after treatment since nits are not contagious. Always contact your doctor if you are unsure if your family has lice, are unable to successfully treat them with the above steps, or have additional questions.
Wishing you a happy and lice free school year!
Frequently Asked Questions About Head Lice
How do children get head lice?
Head lice spread almost exclusively through direct head-to-head contact. They cannot jump or fly. Indirect spread through shared hats, helmets, headphones, hair accessories, or pillowcases is possible but much less common. Lice die within 1–2 days off the scalp.
What are the signs my child has head lice?
The most common symptom is itching of the scalp, particularly at the back of the head and behind the ears. However, some children have no itching at all. To check: look carefully at the scalp under bright light, parting the hair in sections. Lice are small (sesame seed-sized), gray or tan, and move quickly. Nits (eggs) look like tiny white or yellow-tan oval specks firmly attached to individual hair shafts, usually within a centimeter of the scalp — unlike dandruff, they cannot be flicked off easily.
What is the most effective treatment for head lice?
For most cases, permethrin 1% (Nix) applied to dry hair is the recommended first-line OTC treatment. Apply to dry hair, leave for 10 minutes, rinse, and repeat exactly 9 days later. The second treatment is essential — it kills lice that hatched from eggs after the first application. Follow up with a fine-toothed nit comb. If OTC treatment fails after two rounds, call Spring Valley Pediatrics — prescription treatments (Sklice or Natroba) are highly effective.
Do I need to wash all the bedding and stuffed animals?
Wash bedding, clothing, and recently worn items in hot water (130°F or higher) and dry on high heat. Items that cannot be washed can be placed in a sealed plastic bag for 2 weeks. Vacuum upholstered furniture and carpets. Fumigant sprays are not necessary. Focus energy on treating the child’s head, not on extensive environmental cleaning.
When can my child return to school after lice?
The AAP and CDC no longer recommend “no nit” policies. A child who has been treated does not need to be kept home from school. Check your school’s policy — most require treatment before returning, but the presence of some nits after treatment does not require exclusion.
What if the lice treatment is not working?
Resistance to permethrin has been increasing in some areas. If two rounds of permethrin 1% have not resolved the infestation, call Spring Valley Pediatrics. We can prescribe spinosad (Natroba) or ivermectin (Sklice) — both are effective single-application prescription treatments.
How do I check my child’s hair for lice correctly?
Wet the hair and apply conditioner to make combing easier. Use a fine-toothed nit comb and work through the hair in small sections from the scalp outward, wiping the comb on a white paper towel after each stroke. Work under bright light. Pay particular attention to behind the ears and the nape of the neck.
