Lice (Pediculosis Capitis)—Child Care and Schools

Lice are small tan, gray, or white insects less than ⅛ of an inch long that

• – Live on blood they draw from the scalp (head lice).

• – Live for days to weeks depending on temperature and humidity.

• – Crawl. They do not hop or fly.

• – Deposit tiny eggs (smaller than half a grain of rice), known as nits, on a hair shaft 1 to 2 mm (⅛ of an inch) from the scalp.

Families and educators may get very upset about head lice, but it is important to recognize that lice do not spread disease. Infestations can occur in anyone, regardless of socioeconomic status, and are not a reflection of poor hygiene. Disrupting normal activities because of concerns about lice is unnecessary.

Itching or scratching of skin where lice feed on the scalp, behind the ears, or on the neck. Lice can be present for weeks before itching occurs.

Itching results from an allergic reaction to louse saliva and, sometimes, from the treatment itself; itching often persists for weeks after the infestation has resolved.

Nits attached to hair, and adult lice, can be seen most easily behind ears and at or near the nape of the neck.

Louse infestations can cause irritation, itching, and scratching, which can lead to secondary skin infection. Open sores and crusting from infections can cause swollen lymph nodes (glands).

Lice are most active at night, which can lead to irritability and sleeplessness.

Incubation period: 7 to 12 days from laying to hatching of eggs. Lice can reproduce about 2 weeks after hatching if close to the scalp.

Contagious period: Until live lice are no longer present.

Head lice are unlikely to transmit from one child to another in schools.

Lice are spread primarily through direct head-to-head contact with infested hair, which may uncommonly occur in early childhood education (ECE) programs. Shared objects (eg, hats, combs, hairbrushes) that contact the head can spread lice, but this is uncommon because lice prefer to stay close to the scalp’s blood supply.

The eggs need the warmth from the scalp for hatching. The nits that are more than ¼ of an inch from the scalp have already hatched or have died. Adult insects cannot live for more than 24 hours away from the scalp.

Treatment only if there is an active infestation of lice (ie, at least 1 live, crawling louse). The presence of nits alone does not require treatment. Treatment involves medications (pediculicides) that kill lice and nits. These chemicals are toxic to lice and may have some toxicity to humans, especially if they are not used according to manufacturers’ instructions or if they are used for age-groups for which the product is not recommended. If a particular chemical fails, repeated use is unlikely to be successful, and an alternative, effective treatment should be tried.

Herbal and “natural” remedies (eg, ylang-ylang, tea tree, lavender oils) are not regulated by the US Food and Drug Administration, so their safety and effectiveness are uncertain. Household products (eg, salad oils, mayonnaise, petroleum jelly) have not proven effective, and some (eg, kerosene) are dangerous. Noninsecticidal occlusive agents like dimethicone and isopropyl myristate show some promise.

Mechanical removal of the lice and nits by combing them out of wet hair with a special fine-tooth comb may have some benefit compared with no treatment. It also may reduce confusion about whether the child has been successfully treated or is re-infested with lice. This treatment is tedious and very time-consuming, especially if the person infested with lice has long hair, hair extensions, or a hair style that involves extensive braiding. It requires washing the hair, applying conditioner, separating the hair into small sections to comb it thoroughly, and then repeating until no new nits are seen within ¼ of an inch from the scalp. It is unknown whether combing improves treatment success rates if the child is already receiving a chemical treatment at the same time.

Household and close contacts should be examined and treated if they have infestations. Individuals who share the same bed with the infested child may also be treated, even if bedmates have no live lice.

Discourage activity that causes head-to-head contact if an infestation is identified. Head lice are rarely transferred by items that contact the head.

The following supplemental measures are options, not requirements, because spread is primarily from head to head:

• – Launder articles in contact with the infested individual in the 2-day period before treatment by exposing them to temperatures greater than 130 °F (54.4 °C) for 5 minutes, followed by drying on a hot setting. Alternatively, clothing and bedding can be dry-cleaned.

• – Items that cannot be washed or dry-cleaned, such as toys, bedding, other fabrics, and upholstered furniture, can be sealed and stored in a plastic bag for 2 weeks.

• – Vacuum, floors, carpets, mattresses, and furniture to remove any hair with viable louse eggs. Chemical treatment of the environment is not necessary.

• – A chemical treatment (pediculicide) spray of the environment is not necessary and should not be used.

Report the infestation to the staff member designated by the ECE program or school for decision-making and action related to care of ill children and staff members. That person, in turn, alerts possibly exposed family and staff members to watch for symptoms.

Educate parents/guardians on the diagnosis of louse infestation. They can screen their children’s heads for lice regularly and if the child has symptoms. Have parents/guardians consult with a health professional for a treatment plan if they have a louse infestation.

Check children observed scratching their heads for lice; if lice are found, check all contacts.

Teach educators and families how to recognize lice and nits. Nits remain attached to hair even when dead, so their presence (especially >1 cm from the scalp) is not a definite sign of an active infection.

ECE setting: Treatment may be delayed until the end of the day. If treatment is started before return the next day, no exclusion is needed.

School setting: No. School-aged children should not be excluded or sent home early from school because of head lice because head lice have a low contagion within classrooms.

Parents/caregivers of children with a louse infestation should be notified and informed that their child should be treated.

A “no-nit” policy that requires a child to be free of nits before they return to class is discouraged. These policies are ineffective at controlling outbreaks, may unnecessarily exclude children from the program, and place undue burden on parents/guardians.