Head lice (Pediculus humanus capitis) are tiny, wingless insects that live on the human scalp and feed on blood. These infestations, called pediculosis, are common, particularly among preschool and elementary-aged children, affecting millions annually in the United States. Understanding the current guidelines and treatment steps is important for managing the situation effectively.
Current School Attendance Policies Regarding Head Lice
The question of whether an infested child must be removed from the classroom has undergone a significant shift in recent years. Major health organizations like the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) now recommend against the immediate exclusion of a student found to have head lice. Students can typically remain in class until the end of the school day, allowing them to go home and begin treatment that evening.
This modern approach discourages “no-nit” policies, which previously required a child to be completely free of eggs (nits) before returning to school. These policies are considered unnecessarily disruptive to a child’s education and place an undue burden on families. The reasoning is that nits are firmly attached to the hair shaft and are unlikely to transfer to another person.
A child should be allowed to return to school immediately after the first treatment application has been completed at home. Nits found far from the scalp are often hatched casings or non-viable eggs that will never produce a live louse. Allowing immediate return prevents unnecessary academic disadvantage and psychological stress associated with exclusion.
How to Identify and Confirm a Head Lice Infestation
Proper diagnosis relies on finding a live louse or a firmly attached nit close to the scalp. Head lice crawl, do not jump or fly, and are about the size of a sesame seed when fully grown. The most common areas to check are the hair behind the ears and at the nape of the neck, as these spots provide the warmth lice prefer.
Nits are the oval-shaped, yellowish or whitish eggs laid by adult female lice. They are glued securely to the hair shaft near the base, which distinguishes them from dandruff or hair spray droplets that can be easily brushed away. Live nits require the warmth of the head to hatch and are usually located within 6 millimeters (about a quarter-inch) of the scalp.
The eggs hatch into nymphs, which mature into adult lice. Finding nits located further down the hair shaft suggests an older, likely inactive infestation that may not require treatment if no live crawling lice are observed. Using a bright light and parting the hair to look closely at the scalp is the most effective way to confirm an active infestation.
Effective Home Treatment and Follow-Up Care
Treatment should only begin once an active infestation has been confirmed by finding a live louse or viable nits near the scalp. Over-the-counter (OTC) pediculicides, such as products containing pyrethrins or permethrin, are common first-line treatments. These products work by poisoning the louse, but they may not kill all the nits, requiring a second application.
Following the manufacturer’s instructions is important, as many treatments require a second application on day seven to ten to kill newly hatched lice before they can lay new eggs. If an OTC treatment fails, a healthcare provider may recommend a prescription medication, such as lotions that may not require retreatment.
Mechanical removal using a fine-toothed nit comb is an important component of successful eradication. This is often performed on wet hair with conditioner to make the lice more visible and easier to remove. After each treatment and for the following two to three weeks, the hair should be checked and combed every two to three days to remove any remaining nits or lice.
Lice cannot survive for long away from a human host, typically dying within one to two days, so excessive house cleaning is not necessary. Items that have been in contact with the infested person’s head in the two days prior to treatment, such as pillowcases, hats, and bedding, should be machine washed and dried using hot water and high heat settings. Combs and brushes can be sanitized by soaking them in hot water (at least 130 degrees Fahrenheit) for five to ten minutes.