Head Lice (Pediculosis)

Head lice (pediculosis) is not a reportable disease in Oklahoma. Head lice are parasitic insects called Pediculus humanus capitis, which are commonly found in a human’s hair, eyebrows, and eyelashes. Head lice can cause irritation to the scalp or other areas when the organism feeds on blood at the surface of the skin. Head lice rely on the warmth of their hosts to reproduce. The insect, Pediculus humanus capitis, is roughly the size of a sesame seed. Head lice can crawl very quickly, but cannot jump or fly.

There are three forms of lice: egg, nymph, and adult. The eggs (nits) are very small, hard to see, and are often confused with dandruff or hair spray droplets. They are oval and usually yellow to white. Nits are laid by the adult female at the base of the hair shaft near the scalp, firmly attached to the hair shaft, and take about 1 week to hatch. The nit hatches into a baby louse (nymph), which feeds on the blood of the host. Nymphs mature into adults (louse) about 7 days after hatching. The adult louse is about the size of a sesame seed, has six legs, and is tan to grayish white. Adult lice can live up to 30 days on a person’s head.

The most common sign of a recent head lice infestation is itching of the head and scalp, particularly at the back of the head and around the ears. Itching can also be the result of an allergic reaction to the bites. An individual may also experience a tickling feeling of something moving in the hair. As a symptom of scratching, sores may be present on an individual’s scalp. Diagnosis is performed by a trained person who searches for signs of the insects in the hair and scalp. Because lice are quick moving and may not be easily seen, finding eggs within ¼ inch of the scalp is confirmation of an infestation.

Anyone who comes in direct contact with someone who already has head lice is at risk of infestation. Head lice may also be acquired from contact with clothing (such as hats, scarves, coats) or other personal items (brushes or towels) that belong to an infested individual. Transmission of both live insects and eggs can result in infestation.

Head lice are treated with medication and manual removal. Pediculocides are prescription medications directly applied to infested areas that kill head lice. It is important to remove as many lice and nits as possible.

How to prevent head lice infestation:

• Teach children not to share clothing, hats, brushes, or combs with other children.
• Make head checks part of routine hygiene. Check children’s heads as soon as signs of infestations occur. The earlier lice are found, the easier they are to treat.
• Teach children to hang coats and other personal belongings so that they don’t touch the coats or personal belongings of other students.
• Work with schools as necessary to eliminate head lice.

ADS Resources:
Head Lice Fact Sheet  En Espanol
Public Health Recommendations for Head Lice Control in Schools and Daycares
Sample Letters
Head Lice Control Measure Tip Sheet
Household Cleaning Instructions for Louse Control 
How to Comb Hair to Remove Nits
Reference Table of Pediculocides by Chemical Name
Reference Table for Head Lice Treatments
Lice Manipulation Calendar
Head Lice Treatment Calendar
How to Treat Head Lice
Questions and Answers about Head Lice
The Do's and Dont's of Treating Head Lice
Internet Resources
References

Other Resources:
CDC Head Lice
National Pediculosis Association