A common complaint in the first weeks after school has resumed is head lice. These tiny parasites can cause itching and discomfort, but are generally harmless. Making the correct diagnosis, then treating and preventing the infestation will be covered in this article. Being told your child has head lice can be greatly distressing to parents and the child. This article will also address some of the myths and frequently asked questions about head lice.
What are head lice? The head louse (pediculosis capitus) is a parasitic insect that lives on the human hair/scalp, eyebrows and eyelashes. Lice feed on the blood of the host they infest. It has a 3 stage life cycle beginning with egg (nit), which hatches and produces a nymph which then matures to an adult. The adult is 2-4mm in size (about the size of a sesame seed) and can only crawl. It cannot hop or fly. All 3 stages require a human host to stay alive. Dogs and cats cannot be infested nor transmit the lice. The lice also require a human to feed on and so quickly die after being separated from the host. Adult lice can live only 1-2 days without feeding.
Where does the infection come from? Head lice are transmitted from head to head contact primarily among school age and preschool age children. Rarely, sharing brushes/combs or hats can also cause spread.
What are the symptoms of lice infection? The primary symptom is itching scalp and the feeling that something is crawling on the scalp. There are usually red bumps present at the nape of the neck or elsewhere on the scalp where the person has been bitten by the lice. Scratching, by the way can cause these bites to get infected from bacteria on the skin. Nits are also present, usually located at the base of the skull and surrounding the ears. The nits are white/clear, small and oval shaped. They are tightly adhered to the hair shaft and can be difficult to remove. Active nits are typically close to the scalp (within ¼ of an inch) and so nits that are further down the hair shaft usually represent an old infestation, not an active one.
How can I tell if my child has lice? Adult lice and nits can be seen with the naked eye, though magnification will help. Seeing an adult louse is the most obvious way to make the diagnosis. However, adult lice crawl very fast and avoid the light so are very hard to see. Seeing nits adhered to the hair shaft within ¼ of an inch from the scalp as well as the symptoms of itching and bug bites to the scalp will often be enough to diagnose head lice and begin treatment. How to treat head lice:
1. Buy an over the counter pediculoside (Nix, Rid, Ovid) and use strictly according to the package directions. Remember as mentioned above that lice, though annoying, are harmless and over treating can be a problem for the child.
2. Wash any sheets, pillow cases, towels, hats and clothing that the child has come in contact with for the last 2 days in hot (>130 degree) water. Anything that cannot be washed can be sealed in a plastic bag and put away for 2 weeks.
3. Vacuum around the bed and the floor where the child has been lying down. There is no reason to treat furniture/carpets with pesticides.
4. Remove nits using a nit comb
5. Retreat after all the eggs have hatched (typically 9 days) and inspect for evidence of on-going infection.
Common myths associated with head lice:
1. Head lice do not come from being dirty- they are only spread from head to head contact.
2. Head lice do not hop, jump or fly.
3. Head lice do not carry diseases.
4. Nits in the hair, if old and further than ¼ inch from the scalp, do not mean there is an active infection.
Further information can be obtained from the CDC web site: www.cdc.gov.
