Lice, Head and Body Lice (Pediculosis)
Lice, Head and Body Lice (Pediculosis) is are tiny insects that can live on the scalp. They can create a tickling feeling or a sensation of something moving in the hair, irritability, and sleeplessness. They are spread most commonly by close person-to-person contact.
Head lice infestations may have no symptoms, particularly with a first infestation or when an infestation is light. Itching is the most common symptom of head lice infestation and is caused by an allergic reaction to louse bites. It may take 4-6 weeks for itching to appear the first time a person has head lice.
How It Spreads
Head lice are spread most commonly by direct head-to-head (hair-to-hair) contact. However, much less frequently they are spread by sharing clothing or belongings onto which lice have crawled or nits nits (head lice eggs) attached to shed hairs may have fallen. The risk of getting infested by a louse that has fallen onto a carpet or furniture is very small.
- Avoid head-to-head (hair-to-hair) contact during play and other activities at home, school, and elsewhere (sports activities, playground, slumber parties, camp).
- Do not share clothing such as hats, scarves, coats, sports uniforms, hair ribbons, or barrettes.
- Do not share combs, brushes, or towels. Disinfest combs and brushes used by an infested person by soaking them in hot water (at least 130°F) for 5-10 minutes.
- Do not lie on beds, couches, pillows, carpets, or stuffed animals that have recently been in contact with an infested person.
- Machine wash and dry clothing, bed linens, and other items that an infested person wore or used during the two days before treatment using the hot water (130°F) laundry cycle and the high heat drying cycle. Clothing and items that are not washable can be dry-cleaned OR sealed in a plastic bag and stored for two weeks.
- Vacuum the floor and furniture, particularly where the infested person sat or lay. However, spending much time and money on housecleaning activities is not necessary to avoid reinfestation by lice or nits that may have fallen off the head or crawled onto furniture or clothing. Head lice only live for a matter of hours off the scalp.
- Do not use fumigant sprays or fogs; they are not necessary to control head lice and can be toxic if inhaled or absorbed through the skin.
Testing & Diagnosis
The diagnosis of head lice infestation is best made by finding a live nymph (newly hatched louse) or adult louse on the scalp or hair of a person.
Because adult and nymph lice are very small, move quickly, and avoid light, they may be difficult to find. Using a fine-toothed louse comb may help you identify live lice.
Treating an infested person requires using an over-the-counter (OTC) or prescription medication (also called pediculicide). Follow these treatment steps:
- Before applying treatment and as helpful, remove clothing that can become wet or stained during treatment.
- Do not use a combination shampoo/conditioner or conditioner before using lice medicine.
- Apply lice medicine according to the instructions contained in the box or printed on the label. If the infested person has very long hair (longer than shoulder length), it may be necessary to use a second bottle. Pay special attention to instructions on the label or in the box regarding how long the medication should be left on the hair and how it should be washed out.
- Have the infested person put on clean clothing after treatment.
- If a few live lice are still found 8-12 hours after treatment, but are moving more slowly than before, do not retreat. The medicine may take longer to kill all the lice. Comb dead and any remaining live lice and nits out of the hair using a fine-toothed nit (head lice egg) comb. Nit combs are often found in lice medicine packages. Many flea combs made for cats and dogs are also effective.
- If, after 8-12 hours of treatment, no dead lice are found and lice seem as active as before, the medicine may not be working. Do not retreat until speaking with your healthcare provider; a different lice medicine may be necessary. If your health care provider recommends a different medicine, carefully follow the treatment instructions contained in the box or printed on the label.
- Nit (head lice egg) combs, often found in lice medicine packages, should be used to comb nits and lice from the hair shaft. Many flea combs made for cats and dogs are also effective.
- After each treatment, checkg the hair and combing with a nit comb to remove nits and lice every 2-3 days. This may decrease the chance of self-reinfestation. Continue to check for 2-3 weeks to be sure all lice and nits are gone.
- Retreat as recommended. Retreatment generally is recommended for most prescription and non-prescription (over-the-counter) drugs on day nine to kill any surviving hatched lice before they produce new eggs. However, if using the prescription drug malathion, retreatment is recommended after 7-9 days only if crawling bugs are found. This is because malathion can destroy the ova, or female reproductive cells.