Head lice and Organo-phosphates.

Brian Hiestand hiestand.2 at pop.service.ohio-state.edu
Sun Dec 8 11:04:14 EST 1996

In article <19961208.114312.93 at halmarax.demon.co.uk> Tony at halmarax.demon.co.uk (Tony Halmarack) writes:
In article <19961208.114312.93 at halmarax.demon.co.uk> Tony at halmarax.demon.co.uk (Tony Halmarack) writes:
>From: Tony at halmarax.demon.co.uk (Tony Halmarack)
>Newsgroups: bionet.toxicology
>Subject: Head lice and Organo-phosphates.
>Date: Sun, 08 Dec 1996 11:43:12 +0100
>Organization: GooseIsland
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>Message-ID: <19961208.114312.93 at halmarax.demon.co.uk>
>Reply-To: Tony at halmarax.demon.co.uk
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>I live at a boarding school which my wife and daughter attend for various
>reasons. For some time there has been a head-louse infestation, treated
>with Organo-phosphates. I'm very unhappy with two aspects of this. 
>The use of these particular chemicals in the first place and the
>ineffective piece-meal methods employed.
>Please can anyone advise as to alternative treatments and procedures?
>Tony Halmarack =*= Tony at halmarax.demon.co.uk

Two alternatives currently in use in US (may be others, but these are common):

1. Nix (permethrin):paralyzes lice by disrupting sodium channels in nerve 
cells.  Also ovicidal, persists in hair.  Ususally only requires one 
treatment at 1% for lice, higher for scabies.  Shampoo, rinse, towel dry, 
apply 1% solution, leave on for 10 min,rinse.  We used this at Children's 
Hospital in Columbus OH for a patient discovered to have lice.  Adverse 
effects usually limited to itching, stinging, or numbness in a small % of 

2. Kwell (lindane):  kills adult lice, some ovicidal activity.  More side 
effects, some resistance known.  Adverse effects due to absorption through 
skin, secondary to too frquent application, prolonged application.

In addition, bedding and clothes, esp hats, all need to be cleaned.  To my 
understanding, regular detergents will do the job, but I am not sure about 
that.  "Personal articles can be disinfested by washing in hot water and/or 
drying using the hot cycle of the dryer.  Eggs are killed after five minutes 
at 51.5 C, or 30 minutes at 49.5 C; adults succumb to slightly lower 
temperatures.  Combs can be disinfested by soaking for one hour in Lysol 
(saponated cresol solution) or heating in water to about 60 C for 5-10 min.  
Clothing or bedding that cannot be washed should be dry cleaned or selaed in a 
plastic bag for two weeks.  Thorough vacuuming will suffice for living 

Malathion is the only organophosphate allowed for this use in the US, is one o 
fthe least toxic OP preparation, and is more ovicidal than Nix or Kwell.  Odor 
is objectionable, and the lotion is flammable-no cigarretes, please!

Source:American Medical Association Drug Evaluations Annual 1995

Brian Hiestand
OSU College of Medicine

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