Head Lice

Head lice

Lice are small, wingless, grayish-tan parasites that feed on the blood vessels in the scalp. They live in the hair of humans and can be passed from person to person by direct contact or on shared objects such as combs, towels, barrettes, pillows, or headphones. Lice are rarely on the body, eyelashes or eyebrows. If a lice infestation is suspected, every member of the family should be checked. The most common symptom is intense itching on the back of the head or neck. Other symptoms include a tickling feeling of something moving in the hair, irritability, or sores on the head.

If lice are suspected, it is important that a definite diagnosis be made. This is done by combing the hair with a fine-toothed comb (also called a nit comb) and inspecting the comb for live lice with each combing. The scalp can be inspected closely, but the lice move fast and are difficult to find. When not sure if there are lice present, a healthcare provider can examine them with a microscope or magnifying glass.

Head lice can be easily treated with medicated shampoos or lotions. These can be purchased over-the-counter or can be prescribed by a healthcare provider. It may take more than one application of the medicated shampoo or lotion to completely get rid of the lice. Treatments should be spaced 7 to 10 days apart to make sure that all the lice are killed. After using the anti-lice medication, the dead nits will remain.

Because nits can be hard to remove, it is usually necessary to use a fine-toothed comb to comb them out of the hair. Continue to use the fine-toothed comb daily to remove all the dead nits. This may take 2 to 3 weeks.

Removing nits can be made easier by soaking the hair with a solution of equal parts of water and white vinegar. A towel dampened with this solution can be left on the hair for 30 to 60 minutes. This makes it easier to remove the nits with a fine-toothed comb.

There are many home remedies that have been tried such as mayonnaise, olive oil, or petroleum jelly. None of these have been proven to work.

Treatments for head lice can be very toxic, regardless of whether they are over-the-counter or prescription treatments. They should never be used more times than recommended. They should not be used if the scalp is infected, which can happen when the louse bites are scratched. Always follow the instructions given for the specific treatment.

Pregnant women should not use any over-the-counter medications without the permission of the healthcare provider. This includes any treatments for head lice.

To easily take care of a head lice problem, follow these guidelines:

Examine the scalp of every member of the family. Look for tiny white eggs (also called nits) on the hair shafts, near the scalp, at the nape of the neck, and behind the ears. Any family member with lice or nits must be treated.
Use an effective head lice treatment.
Wash clothes, bed linens, and towels. Use hot water, then dry on the hot cycle for at least 20 minutes. Items such as stuffed animals, headphones, and hats that are not machine washable must be dry-cleaned or stored at room temperature in a tightly sealed plastic bag for at least 2 weeks.
Soak combs, brushes, and other hair styling aids in hot water for at least 10 minutes. The water temperature should be at least 130 degrees Fahrenheit (54.4 degrees Centigrade), or hotter.
Vacuum everywhere. Make sure the rest of your home is louse-free. Vacuum carpets, pillows, mattresses, upholstered furniture, and car seats.
Recheck for signs of nits in the hair 2 weeks after treatment.
Check with your provider before re-treating.

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.