Summary about Disease
Head lice are tiny, wingless insects that live on the human scalp and feed on blood. They are a common nuisance, especially among school-aged children. Head lice are not a sign of poor hygiene and do not spread disease. Treatment is usually effective in eradicating the lice and their eggs (nits).
Symptoms
Intense itching of the scalp
Feeling of something tickling or moving in the hair
Visible lice on the scalp or hair
Nits (lice eggs) on hair shafts (often appearing as tiny white or yellowish dots firmly attached to the hair close to the scalp)
Sores on the scalp from scratching (sometimes these sores can become infected)
Causes
Head lice are primarily spread through direct head-to-head contact with an infested person. Less commonly, they can spread through sharing personal items like:
Hats
Scarves
Combs
Brushes
Pillows
Upholstery
Medicine Used
Over-the-counter (OTC) medications: Permethrin lotion 1% (Nix) and pyrethrin-based products (Rid).
Prescription medications: Malathion lotion 0.5% (Ovide), benzyl alcohol lotion 5% (Ulesfia), spinosad topical suspension 0.9% (Natroba), ivermectin lotion 0.5% (Sklice). Oral ivermectin is also an option in some cases.
Important Note: Follow the specific instructions on the product label or from your doctor. Retreatment is often necessary.
Is Communicable
Yes, head lice are highly communicable.
Precautions
Avoid head-to-head contact with infested individuals.
Do not share personal items such as combs, brushes, hats, scarves, and pillows.
Wash potentially contaminated items (bedding, clothing, etc.) in hot water and dry on high heat.
Vacuum carpets and upholstered furniture.
Inform close contacts (e.g., school, daycare) if an infestation is identified.
How long does an outbreak last?
Without treatment, a head lice infestation can persist indefinitely. With proper treatment and adherence to precautions, the outbreak can be resolved within a few weeks.
How is it diagnosed?
Diagnosis is typically made by visually identifying live lice or nits on the scalp and hair. A fine-toothed comb can be helpful to search for lice and nits.
Timeline of Symptoms
Initial Infestation: Itching may not begin immediately. It can take several weeks (2-6 weeks) after the initial infestation for itching to develop as the person becomes sensitized to the lice saliva.
Nits: Nits are laid close to the scalp and hatch in about 7-10 days.
Lice Maturation: Newly hatched lice (nymphs) mature into adults in about 9-12 days.
Ongoing Infestation (without treatment): The cycle continues, with adult lice laying more eggs and perpetuating the infestation.
Important Considerations
Resistance: Lice can develop resistance to certain treatments. If OTC medications are ineffective, consult a doctor for prescription options.
Retreatment: Following product instructions and retreatment guidelines are crucial for complete eradication.
"Nit-picking": Removing nits, although time-consuming, can help prevent re-infestation.
School/Daycare Policies: Be aware of your school or daycare's policies regarding head lice.
Prevention: Regular checks, especially in children, can help detect and treat infestations early.