Lice

Background

  • Caused by Pediculus humanus
  • Hats/combs may act as fomites
Lice (electron microscope)

Clinical Features

  • May see live mites or nits (egg sacks) on hair shaft close to scalp
  • May be asymptomatic or pruritic

Differential Diagnosis

Ectoparasites

Evaluation

  • Generally a clinical diagnosis

Management

Over the Counter (OTC)

  • Permethrin 1% lotion shampoo (if >2 months old)[1]
    • Wash hair with non-conditioned shampoo
    • Apply Permethrin for 10 min and rinse
    • Repeat on day 9
  • Pyrethrin lotion
    • Apply to affected areas and wash off after 10 min
    • Repeat in 7 days

Prescription

Reserved for failed OTC treatment

  • Spinosad 0.9% topical suspension (if >6 months old)
    • Apply to scalp and air and wash off after 10 min.
    • Repeat in 10 days
  • Malathion 0.5% lotion (if >6 years old)
    • Applied to affected areas and wash after 8 hrs
    • Repeat in 7 days
  • Benzyl Alcohol 5% lotion (> 6 months old)
    • Apply to dry hair and wash off after 10 min
    • Repeat in 7 days
  • Ivermectin 400mcg/kg PO
    • Once on day 1 THEN once in 7 days
    • Reserved for patients failing topical treatment
  • Lindane therapy
    • Only consider if patient has failed two prior prescription treatments
    • Avoid in children <50 kg due to seizure association

Eyelash Infestation

  • Apply ophthalmic petroleum jelly q12hrs x 10 days

Pediatrics <2yo

  • Wet combing is an alternative to medical therapy

Disposition

  • Discharge
  • Children can return to school after first topical treatment has been applied
  • Instruct parents and all close contacts to wash clothing and bedding in hot soapy water to avoid disease spread

See Also

References

  1. Devore CD and Schutze G. Head Lice. Pediatrics. 2015; 135(5) e1355-e1365.