Can't seem to get an answer to this question. Tacky as it is, here goes: Do you know of an herb that I can infuse or add to my homemade soap that is useful in preventing lice? I have many children with long hair and it is getting that season again (sigh); An ounce of prevention is worth.......alot of my time! :)
Pyrethrum is a herb that is effective against lice. Its active constituents and chemical analogues of them are used in anti-lousing preparations. The dried flowers are used.
We are not sure whether it is a good idea to use pyrethrum as a preventative. Lice are quick to build up resistance to pesticides and continual use could speed that up. Also, although pyrethrum is relatively safe to use on humans, we would be concerned about repeated contact whether or not there is a lice problem. Pyrethrum is better used only to eradicate known infestations (it works best if applied at the early stages of an infestation). With proper use it can clear up infestations without with little risk of resistance building; but with continual, indiscriminate use resistance is sure to build up over time.
Any agent used indiscriminately is likely to cause resistance over time, so this problem is not unique to pyrethrum. A better strategy would be a combination of close monitoring, avoiding contact with lice-infested animals and areas, and judicious use of anti-lousing preparations at the earliest stages of infestations.