Head Lice

Stamp out the scratching and discomfort caused by this common parasite. According to research or other evidence, the following self-care steps may help your family stay free and clear of head lice:

What you need to know

These recommendations are not comprehensive and are not intended to replace the advice of your doctor or pharmacist. Continue reading the full head lice article for more in-depth, fully-referenced information on medicines, vitamins, herbs, and dietary and lifestyle changes that may be helpful.

About head lice

Head lice (Pediculosis capitis) is an infestation of the hair and scalp by a mite called Pediculus capitis. Head lice affects mainly children and the mite can either be passed directly by person to person contact, or indirectly when the organism is deposited on shared articles such as clothing, furniture, bed linens, or hairbrushes.1

Product ratings for Head lice

Science Ratings Nutritional Supplements Herbs
2Stars  

Citronella

Paw paw, thyme oil, and tea tree oil (in combination)

Quassia

Sugar apple
1Star  

Anise, ylang ylang, and coconut oils (in combination)

Sassafras
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

What are the symptoms?

Itching of the scalp, which can be very intense, is the most common symptom of head lice. There may be small crusts of dried blood around sites where bites have occurred, and combing with a fine-tooth comb may pick up eggs (nits) that have been attached to the hair shaft.2 3

Lifestyle changes that may be helpful

Maintaining a clean personal environment is essential for the prevention and control of head lice. This means that clothing, bedding, and personal hair care items such as brushes and combs should be washed regularly. Regular vacuuming of floors, furniture, and play areas will remove hairs that might harbor nits.4

Head lice and their eggs may be removed by using hair conditioner, followed by combing through the wet hair with a fine-tooth comb.5

Herbs that may be helpful

Constituents of the essential oils found in certain herbs have been shown in test tube studies to be toxic to head lice and their eggs.6 7 Specific oils with the highest activity include eucalyptus, marjoram, pennyroyal, and rosemary oils.8 None of these specific oils, however, has been tested in human studies.

Quassia (Quassia amara) is a tree native to the Amazon rainforest that has constituents with activity against several types of microbes and insects.9 10 11 An uncontrolled study reported that all but three out of 454 cases of head lice were successfully treated with a topical tincture of quassia bark applied to the scalp once, and again one week later.12 A double-blind trial found that using a similar quassia extract helped prevent new cases of head lice.13

Citronella is the volatile oil extracted from Cymbopogon nardus or Cymbopogon winterianus. In a double-blind trial, children with head lice were treated either with a placebo lotion or a lotion containing 3.7% citronella in a slow-release formula.14 The lotions were sprayed on the hair every morning for six days each week. Reexamination after two and after four months showed that significantly fewer children using citronella lotion were still infested.

A commercial product (HairClean 1–2-3) containing oils of anise, ylang ylang (Cananga odorata), and coconut, plus isopropyl alcohol, which, when applied once per week for 15 minutes followed by rinsing, shampooing, and combing, was 98% effective, according to a preliminary report.15

Sugar apple (Annona squamosa) is a tree native to Latin America, the Caribbean, and Southeast Asia. In a controlled trial, a cream containing 20% oil of sugar apple seed killed 95% of head lice when applied once to the hair of infested schoolgirls for three hours, and then washed out.16

An herbal shampoo (Paw Paw Lice Remover Shampoo) containing a standardized extract of paw paw (Asimina triloba), thyme oil, and tea tree oil was found to be toxic to head lice in test tube studies, after which uncontrolled trials were carried out in 13 families.17 The shampoo was applied to the dry hair and left on for one hour before washing out and combing with a fine-tooth comb; this was repeated eight and sixteen days later, after which 100% of the 37 participants were free of lice.

Traditional herbalists recommend applying oil of sassafras topically three times per day for lice, but this has never been tested in a clinical study.18

Are there any side effects or interactions?
Refer to the individual herb for information about any side effects or interactions.

Holistic approaches that may be helpful

Several home remedies have been popularized for treating head lice, including topical application of isopropyl alcohol, olive oil, mayonnaise, melted butter, and petroleum jelly. Test tube studies of these remedies found that only petroleum jelly was effective for killing lice and their eggs,19 but no human studies have investigated whether any home remedy is an effective treatment for an existing infestation.

References

1. Freedberg IM, Eisen AZ, Wolff K, et al, eds. Fitzpatrick's Dermatology in General Medicine (6th Edition). New York: McGraw-Hill, 2003, page 2286.

2. Freedberg IM, Eisen AZ, Wolff K, et al, eds. Fitzpatrick's Dermatology in General Medicine (6th Edition). New York: McGraw-Hill, 2003, page 2286.

3. De Maeseneer J, Blokland I, Willems S, et al. Wet combing versus traditional scalp inspection to detect head lice in schoolchildren: observational study. BMJ 2000;321:1187–8.

4. Freedberg IM, Eisen AZ, Wolff K, et al, eds. Fitzpatrick's Dermatology in General Medicine (6th Edition). New York: McGraw-Hill, 2003, page 2288.

5. Frydenberg A, Starr M. Head lice. Aust Fam Physician 2003;32:607–11.

6. Priestley CM, Burgess IF, Williamson EM. Lethality of essential oil constituents towards the human louse, Pediculus humanus, and its eggs. Fitoterapia 2006;77:303–9.

7. Yang YC, Lee HS, Lee SH, et al. Ovicidal and adulticidal activities of Cinnamomum zeylanicum bark essential oil compounds and related compounds against Pediculus humanus capitis (Anoplura: Pediculicidae). Int J Parasitol 2005;35:1595–600.

8. Yang YC, Lee HS, Clark JM, Ahn YJ. Insecticidal activity of plant essential oils against Pediculus humanus capitis (Anoplura: Pediculidae). J Med Entomol 2004;41:699–704.

9. Ajaiyeoba EO, Krebs HC. Antibacterial and antifungal activities of Quassia undulata and Quassia amara extracts in vitro. Afr J Med Med Sci 2003;32:353–6.

10. Gilbert B, Teixeira DF, Carvalho ES, et al. Activities of the Pharmaceutical Technology Institute of the Oswaldo Cruz Foundation with medicinal, insecticidal and insect repellent plants. An Acad Bras Cienc 1999;71:265–71.

11. Evans DA, Raj RK. Larvicidal efficacy of Quassin against Culex quinquefasciatus. Indian J Med Res 1991;93:324–7.

12. Jensen O, Nielsen AO, Bjerregaard P. Pediculosis capitis treated with quassia tincture. Acta Derm Venereol 1978;58:557–9.

13. Ninci ME. Prophylaxis and treatment of pediculosis with Quassia amarga. Rev Fac Cien Med Univ Nac Cordoba 1991;49:27–31 [in Spanish].

14. Mumcuoglu KY, Magdassi S, Miller J, et al. Repellency of citronella for head lice: double-blind randomized trial of efficacy and safety. Isr Med Assoc J 2004;6:756–9.

15. Meinking TL. Infestations. Curr Probl Dermatol 1999;11:73–120 [review].

16. Tiangda CH, Gritsanapan W, Sookvanichsilp N, Limchalearn A. Anti-headlice activity of a preparation of Annona squamosa seed extract. Southeast Asian J Trop Med Public Health 2000;31 Suppl 1:174–7.

17. McCage CM, Ward SM, Paling CA, et al. Development of a paw paw herbal shampoo for the removal of head lice. Phytomedicine 2002;9:743–8.

18. Hoffmann D. The New Holistic Herbal, 3rd ed. Shaftesbury, Dorset, UK: Element, 1990:230.

19. Takano-Lee M, Edman JD, Mullens BA, Clark JM. Home remedies to control head lice: assessment of home remedies to control the human head louse, Pediculus humanus capitis (Anoplura: Pediculidae). J Pediatr Nurs 2004;19:393–8.