para>Lindane: FDA black box warning of severe neurologic toxicity (use only when first-line agents have failed). The National Pediculosis Association strongly advises against using lindane at all.
GENERAL MEASURES
- Head lice: Clean items that have been in contact with the head of the infected individual within 48 hours.
- Wash all bedding, towels, clothes, headgear, combs, brushes, and hair accessories in hot water (60 °C).
- Vacuum furniture and carpets
- Seal any personal articles that cannot be washed in hot water, dry cleaned, or vacuumed in a plastic bag and store for at least 2 weeks.
- Examine and treat household members and close contacts concurrently.
- Insecticide sprays are not necessary.
- Pubic lice: Avoid sexual activity until both partners are successfully treated.
- Nit and egg removal
- Remove eggs that are within 1 cm of the scalp to prevent reinfestation.
- After treatment with shampoo or lotion, eggs and nits remain in the scalp or pubic hair until mechanically removed. Hair conditioner facilitates nit removal.
- Eggs and nits are best removed with a very fine nit comb.
Pediatric Considerations
Avoid synergized pyrethrin and permethrin in infants <2 months of age. Avoid benzyl alcohol, topical ivermectin, and spinosad in children <6 months of age; and avoid malathion in children <2 years of age.
Lindane: not recommended in patients <50 kg
Pregnancy Considerations
Permethrin, synergized pyrethrin, malathion, spinosad, and benzyl alcohol are pregnancy Category B. Lindane and topical ivermectin are Category C.
ADDITIONAL THERAPIES
- For "difficult to treat " cases of head lice, oral ivermectin 400 ¼g/kg (not approved by the FDA for lice), given twice at a 7-day interval, is superior to topical 0.5% malathion lotion (4,5)[B]
- Ivermectin: 200 ¼g/kg PO repeated in 10 days or 300 ¼g/kg PO repeated in 7 days
- Should not be used in children <15 kg; pregnancy Category C
- Not approved by the FDA for lice
- Dual therapy with 1% permethrin and oral trimethoprim/sulfamethoxazole (TMP/SMX) only for cases of multiple treatment failures or suspected cases of lice-related resistance to therapy (TMP/SMX is not approved by the FDA for lice).
- Permethrin 5% cream (Rx) is not FDA approved for lice and is unlikely to be effective for lice that are resistant to 1% cream rinse (1)[B].
COMPLEMENTARY & ALTERNATIVE MEDICINE
Head lice
- Dry-on, suffocation-based pediculicide: Cetaphil lotion
- Apply thoroughly to hair, comb, dry with hair dryer, shampoo after 8 hours.
- Repeat once a week until cured, up to a maximum of three applications.
- Not approved by the FDA for lice
- Dimethicone 4% lotion: Apply to hair for 8 hours; repeat in 1 week (not approved by the FDA for lice).
- No home remedies (e.g., vinegar, isopropyl alcohol, olive oil, ylang ylang oil, mayonnaise, melted butter, and petroleum jelly) have been proven effective to treat head lice infestations.
- Herbal shampoos and pomades have not been evaluated in clinical trials and are not approved by the FDA for lice.
- Lavender oil and tea tree oil have been implicated in triggering prepubertal gynecomastia in boys and should not be used to treat lice.
- Electronic louse combs have not proven effective and are not approved by the FDA.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Children may return to school after completing topical treatment, even if nits remain in place. No-nit policies are not necessary.
Patient Monitoring
Drug resistance should be suspected if no dead lice are observed in 8 to 12 hours after treatment.
PATIENT EDUCATION
- National Pediculosis Association: http://www.headlice.org/
- CDC: http://www.cdc.gov/parasites/lice/
- http://www.guideline.gov/content.aspx?id=46429&search=lice
PROGNOSIS
- With appropriate treatment, >90% cure rate
- Recurrence is common, mainly from reinfection or treatment nonadherence. Resistance to synthetic pyrethroids is increasing.
COMPLICATIONS
- Poor sleep due to pruritus
- Persistent itching may be caused by too frequent use of the pediculicide.
- Missed school; social stigma
- Secondary bacterial infections
- Body lice can transmit typhus and trench fever.
REFERENCES
11 Devore CD, Schutze GE. Head lice. Pediatrics. 2015;135(5): e1355 " e1365.22 Burgess IF. Current treatments for pediculosis capitis. Curr Opin Infect Dis. 2009;22(2):131 " 136.33 Gunning K, Pippitt K, Kiraly B, et al. Pediculosis and scabies: treatment update. Am Fam Physician. 2012;86(6):535 " 541.44 Chosidow O, Giraudeau B, Cottrell J, et al. Oral ivermectin versus malathion lotion for difficult-to-treat head lice. N Engl J Med. 2010;362(10):896 " 905.55 Feldmeier H. Treatment of pediculosis capitis: a critical appraisal of the current literature. Am J Clin Dermatol. 2014;15(5):401 " 412.
ADDITIONAL READING
- Cole SW, Lundquist LM. Spinosad for treatment of head lice infestation. Ann Pharmacother. 2011;45(7 " 8):954 " 959.
- Durand R, Bouvresse S, Berdjane Z, et al. Insecticide resistance in head lice: clinical, parasitological and genetic aspects. Clin Microbiol Infect. 2012;18(4):338 " 344.
- Pariser DM, Meinking TL, Bell M, et al. Topical 0.5% ivermectin lotion for treatment of head lice. N Engl J Med. 2012;367(18):1687 " 1693.
SEE ALSO
Arthropod Bites and Stings; Scabies
CODES
ICD10
- B85.0 Pediculosis due to Pediculus humanus capitis
- B85.1 Pediculosis due to Pediculus humanus corporis
- B85.3 Phthiriasis
- B85.2 Pediculosis, unspecified
- B85.4 Mixed pediculosis and phthiriasis
ICD9
- 132.0 Pediculus capitis [head louse]
- 132.1 Pediculus corporis [body louse]
- 132.2 Phthirus pubis [pubic louse]
- 132.9 Pediculosis, unspecified
- 132.3 Mixed pediculosis infestation
SNOMED
- 81000006 Pediculosis capitis (disorder)
- 25188002 Pediculosis corporis (disorder)
- 71011005 Infestation by Phthirus pubis (disorder)
- 414618002 louse infestation (disorder)
- 187211004 Mixed pediculus infestation
CLINICAL PEARLS
- School-based no-nit policies are not necessary because empty nits may remain on hair shafts for months after successful eradication.
- Proper product application is essential; consider improper product application when assessing treatment failure.
- Prevalence of resistant infestations is increasing, so if no dead lice are observed in 8 to 12 hours after treatment, suspect resistance and use an alternative agent.
- Routine retreatment on day 9 is recommended for nonovicidal products (permethrin and synergized pyrethrin).
- With all treatment options, reinspect hair after 7 to 9 days and, if live lice are detected, repeat treatment on day 9.