LICE


Treatment:

  • Permethrin
    1. Remains active for >2wks, poorly absorbed from skin; rapidly metabolized and excreted in urine
    2. 1% form (Nix) is available OTC; some resistance has been reported
    3. 5% form (Elimitie) requires prescription; approved only for tx of scabies; can use it applied to clean, dry hair and left on 8-12h under a shower cap
  • Pyrethrins
    1. Natural chrysanthemum extract, us. combined with piperonyl butoxide
    2. Safe, fairly effective (but not as much as permethrin) but with frequent tx failures
    3. Need 2nd tx 5-7d after first b/c don't kill all unhatched eggs
  • Malathion-no longer available in U.S.
  • Lindane
    1. Slow-killing pesticide
    2. 1% shampoo, apply x 4minutes then repeat 1wk later
    3. Probably safe but can have CNS toxicity if overused or ingested; resistance is common with repeated tx
  • Ivermectin
    1. Single PO dose 200ug/kg highly effective for scabies and head lice with "virtually no adverse effects" (Med Letter 1/17/97)