Head lice are a prevalent issue, especially among school-aged children and their families. These tiny insects can cling to anyone's hair, regardless of cleanliness. Head lice are found globally in various environments, from homes and schools to rural and urban areas, and affect people of all socioeconomic backgrounds.

Although head lice are bothersome, they don't cause serious illness or transmit diseases. They can be treated at home, but it's important to consult a doctor first (refer to "Head Lice Medicines" below). Continue reading for tips on detecting, treating, and preventing the spread of head lice.

Understanding Head Lice

Head lice are small insects, about the size of a sesame seed (2–3 mm long). They are usually pale gray but can vary in color. A single insect is called a louse. Head lice feed on tiny amounts of blood from the scalp and can't survive more than a day without feeding.

What Are Nits?

Lice lay eggs, called nits, which they attach to hair close to the scalp. Nits are oval, about the size of a knot in thread (0.8 mm long and 0.3 mm wide), and usually yellow or white. They can blend with hair color, making them hard to see, and are often mistaken for dandruff or hair spray droplets. Nits attach firmly to hair with a sticky substance and remain on the hair shaft even after hatching.

Life Cycle of Head Lice

Head lice live about 28 days and develop in three stages: egg (nit), nymph, and adult louse.

Egg or Nit: Nits hatch in 7 to 12 days, depending on temperature. They are typically found within 4 to 6 mm of the scalp and do not survive if farther away.
Nymph: Nymphs look like adult lice but are smaller (about the size of a pinhead, 1.5 mm). They mature into adults 9-12 days after hatching.
Adult Louse: An adult female can lay up to 10 eggs daily. Newly hatched eggs reach adulthood in about 12 to 14 days.

This cycle can repeat every three weeks if left untreated.

Prevalence of Head Lice

Head lice are most common in preschool and elementary school-aged children. Millions of school-aged children in the United States get head lice each year, though anyone can be affected. Head lice are found worldwide.

Transmission of Head Lice

Head lice crawl and cannot jump or fly. They primarily spread through close, prolonged head-to-head contact. There is a slight chance of spreading through shared items like combs, brushes, hats, and sports helmets.

Symptoms of Head Lice

The primary symptom is itching, especially where lice are present. It may take 4 to 6 weeks after lice infestation for the scalp to become sensitive to lice saliva and begin itching, primarily behind the ears or at the back of the neck. Itching can persist for weeks even after the lice are gone.

Checking for Head Lice

Regular checks can help spot lice before they multiply. Here's how to check:

Find a well-lit area: Seat your child in a brightly lit room.
Part the hair: Look for crawling lice and nits on the scalp section by section.
Use a fine-tooth comb: A louse or nit comb helps search the scalp. Live lice avoid light and move quickly, while nits look like small white or yellow-brown specks firmly attached to hair near the scalp.

Comb-Out Method

The comb-out method can check for and help remove lice and nits after treatment but usually doesn't eliminate lice alone.

Wet the hair.
Use a fine-tooth comb: Comb through the hair in small sections.
Wipe and examine: After each comb-through, wipe the comb on a wet paper towel and examine the towel and scalp.
Repeat: Continue until you've combed through all the hair.

Treating Head Lice

Consult your child's doctor before starting treatment. Head lice medicine is the most effective treatment. Use the comb-out method every 2 to 3 days for 2 to 3 weeks after each treatment to remove nits and eggs. Follow these safety guidelines:

Follow package instructions.
Adult supervision: Only adults should apply the medicine.
Rinse safely: Rinse the medicine off over a sink with warm water.
Safety precautions: Store medicine out of children's reach and never leave a child alone with the medicine in their hair. Consult the doctor before using a second or third medicine.

Warning About Dangerous Home Remedies

Avoid dangerous products like gasoline, kerosene, and animal medicines. Home remedies like petroleum jelly, mayonnaise, tub margarine, essential oils, or olive oil are not proven effective.

Available Head Lice Medicines

Check with your child's doctor for approved treatments. Refer to the provided chart for a list of FDA-approved head lice medicines.

Additional Treatment Tips

Wash items: Wash clothes, towels, hats, and bed linens in hot water and dry on high heat if used within two days before lice treatment.
Avoid pesticides: Do not spray pesticides in your home.
Check and treat all household members: Ensure everyone in the household is checked and treated if necessary.

School "No-Nit" Policies

Some schools have "no-nit" policies, but the American Academy of Pediatrics and National Association of School Nurses discourage these policies. They believe children should not miss school because of head lice.

Remember

Head lice do not pose serious health risks. Use safe products and treat head lice promptly to prevent spreading.