Head Lice in Children
Content reviewed against published AAP, CDC, AAP guidelines
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Head lice are tiny wingless insects that live on the human scalp and feed on blood. They are extremely common in children ages 3-11 and spread through direct head-to-head contact. While they cause intense itching and are a nuisance, head lice do not carry disease and are not a sign of poor hygiene.
Key takeaways
- Head lice are tiny wingless insects that live on the human scalp and feed on blood.
- Duration: With proper treatment, live lice are killed within 24 hours of the first application. A second treatment at 7-10 days is needed to kill lice hatching from surviving eggs. Complete resolution including nit removal takes 2-3 weeks.
- Go to ER if: Severe allergic reaction to lice treatment (difficulty breathing, facial swelling)
- No vaccine currently available
Symptoms
How It Presents by Age
0-2 years
Uncommon in infants and toddlers. When present, usually contracted from an older sibling or close family member. May present mainly as scalp scratching and irritability.
Risk level: Low
2-5 years
Becoming more common as children have closer contact at daycare and preschool. Children at this age have more head-to-head contact during play. Diagnosis requires careful scalp inspection.
Risk level: Low to moderate
5-11 years
Peak age group for head lice infestations. Very common in school-age children. More common in girls than boys due to play patterns and hair length.
Risk level: Moderate (most common age)
11+ years
Less common than school-age children. Spread via sleepovers, sports, and shared items. Self-treatment becomes more feasible.
Risk level: Low to moderate
Treatment
Permethrin 1% lotion (Nix)
First-line over-the-counter treatment. Apply to damp, towel-dried hair after shampooing (without conditioner). Leave on 10 minutes then rinse. Repeat in 7-10 days to kill newly hatched lice.
Dimethicone (silicone-based products)
Suffocates lice by coating them. Available over-the-counter. Apply to dry hair, leave overnight, then comb out dead lice and nits. Repeat in 7 days.
Ivermectin 0.5% lotion (Sklice)
Prescription topical treatment approved for ages 6 months and older. Single application to dry hair for 10 minutes. No repeat treatment needed.
Spinosad 0.9% suspension (Natroba)
Prescription treatment for ages 4 and older. Apply to dry hair for 10 minutes then rinse. Repeat in 7 days if live lice are still seen.
Manual nit removal (wet combing)
Wet hair, apply conditioner, and systematically comb with a fine-toothed nit comb every 3-4 days for 2-3 weeks. Can be used alone or as adjunct to chemical treatment.
Home Care
- Comb wet, conditioned hair with a fine-toothed metal nit comb every 3-4 days for 2 weeks
- Machine wash bedding, clothing, and hats used in the past 2 days in hot water (130F/54C) and dry on high heat
- Seal non-washable items (stuffed animals, pillows) in a plastic bag for 2 weeks
- Vacuum carpets, furniture, and car seats
- Soak combs and brushes in hot water (130F/54C) for 10 minutes
- Check all household members and treat anyone with live lice
- Avoid head-to-head contact with others until treatment is complete
When to Worry
Go to the ER if:
- Severe allergic reaction to lice treatment (difficulty breathing, facial swelling)
- Signs of serious secondary scalp infection with high fever
Call your doctor if:
- First-time infestation and unsure of diagnosis
- Over-the-counter treatments have failed after proper use
- Child is under 2 years old
- Scalp sores show signs of bacterial infection
- Child has a seizure disorder (some treatments are contraindicated)
- Pregnant or nursing mother needs treatment
Keep an eye on:
- Live lice are still present after two rounds of treatment
- Scalp sores appear infected (increasing redness, pus, warmth)
- Child has severe allergic reaction to treatment product
- Infestation keeps recurring despite proper treatment and environmental measures
Prevention
- Avoid head-to-head contact during play and activities
- Do not share combs, brushes, hats, scarves, or hair accessories
- Do not share helmets or headphones
- Perform regular scalp checks, especially during school outbreaks
- Teach children to hang coats and hats separately at school
- Long hair should be pulled back in braids or ponytails
- Regular screening with a nit comb during outbreaks
Contagion & Incubation
Incubation
Eggs (nits) hatch in 7-10 days. Itching may not begin for 4-6 weeks after initial infestation due to the time needed to develop sensitivity to louse saliva.
Contagious for
Contagious as long as live lice or viable nits are present. Adult lice can live 28-30 days on a host. Lice die within 1-2 days if separated from the scalp.
Duration
With proper treatment, live lice are killed within 24 hours of the first application. A second treatment at 7-10 days is needed to kill lice hatching from surviving eggs. Complete resolution including nit removal takes 2-3 weeks.
Frequently asked questions
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Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Illnesses
Bottom line
Head Lice in Children is treatable with appropriate medical care. Seek emergency care if severe allergic reaction to lice treatment (difficulty breathing, facial swelling).
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.