Permethrin is highly toxic to insects but it has a very low mammalian toxicity. Its topical use in humans is very safe for the following reasons:
THROUGH THE SKIN
BY THE LIVER TO INACTIVE
BY THE BODY
DOES NOT CROSS
WHAT IS PEDICULOSIS?
Head lice affects primarily the hair and scalp and the pediculus attach their ova or nits on the hair shafts. The pruritis on the scalp is due to the allergic reaction to their bite. Head lice can be spread through head to head contact and by sharing of personal items such as hats, combs, brushes and hair accessories.
- \First application usually kills the adult mites and lice. Second application after one week kills new mites and lice that have hatched from remaining eggs and nits.
- \Institute anti-pruritic and anti-infective measures where necessary in complicated scabies and pediculosis.
- \All affected members of the family should likewise be treated as these infestations are rapidly spread by contact.
- \Contaminated clothings, beddings and other articles should be washed, boiled, sun or machine dried and ironed. These articles may also be treated with permethrin before washing.
WHAT IS SCABIES?
The recommended concentration of permethrin for pediculosis and scabies is 5%. Concentrations lesser than this has been found to cause resistance. Oral ingestion of permethrin can cause stomach poisoning. Use with caution in babies aged two months and below.