Skip to Main Content
Skip Nav Destination

Treating head lice: Pyrethroids still first-line therapy if pediculicide required

September 26, 2022

Head lice infestation is a frequent source of social anxiety and stress for caregivers, children and adolescents, though it is not responsible for the spread of any infectious disease.

Pediatric providers should know about head lice treatments (pediculicides and alternative therapies) and serve as a resource for families, schools and community agencies.

An updated AAP clinical report offers recommendations for treatment, particularly in refractory cases. It also offers guidance on diagnosis, prevention and control measures in schools and congregate settings.

The report Head Lice, from the Committee on Infectious Diseases, Committee on Practice and Ambulatory Medicine, and Section on Dermatology, is available at and will be published in the October issue of Pediatrics.


The report covers medications available to treat pediculus humanus capitis, including agents approved by the Food and Drug Administration (FDA) since the previous report was published in 2015.

Pyrethroids continue to be first-line therapy of active infestations if pediculicide therapy is required. If a child or adolescent has failed therapy with pyrethroid agents, if the patient is too young for commercially available therapy or if caregivers do not wish to use a pediculicide, then manual removal of lice/nits or occlusive methods are recommended.

A new treatment algorithm offers a stepwise approach for patients with head lice that may be refractory to initial agents. Families should be informed that products without FDA approval for head lice treatment should be avoided, and products intended for animal use are never appropriate in treatment of head lice in humans.

The report also can provide guidance in the following situations.

Q: A 10-year-old complains of itching of the scalp. Nits are seen at the nape of the neck. How long has the child been infested?

A: Itching is an allergic reaction to the saliva of head lice. Individuals need about four to six weeks of exposure to the saliva of head lice to become sensitized. Hair grows at approximately 1 centimeter per month, and nits typically are laid within a centimeter of the scalp. The location of the nits on the hair also may provide a rough estimate of the length of infestation.

Q: A 4-year-old child received first-line pediculicide therapy against head lice. Following treatment, the child still complains of itching and live lice are seen. What pediculicide may be recommended next for the child?

A: Persistent pruritus after treatment does not necessarily denote treatment failure, as it may take several weeks for the itching to subside. After documented failure of pyrethroids (live lice are detected within three weeks of completing therapy), this child may be offered one of three topical agents. Providers can reference the treatment algorithm in the report. The prescriber and caregiver also should consider cost and insurance formulary coverage of agents.

Q: An 18-month-old child is diagnosed with head lice during child care. Does the child need to leave child care, and when can he or she return?

A: The child does not need to leave immediately but should not have close direct head contact with other children. Although treatment is encouraged prior to child care or school re-entry, the AAP and the National Association of School Nurses do not endorse “no nit” policies.

Dr. Nolt is a lead author of the clinical report and a former member of the Committee on Infectious Diseases.


Close Modal

or Create an Account

Close Modal
Close Modal