Lyclear dermal cream contains the active ingredient permethrin which is an insecticide used to treat scabies and crab licescabies is a skin infection caused by the mite sarcoptes scabiei it is characterised by severe itching particularly at night red spots and may lead to a secondary infection permethrin kills this mite and so is useful in the treatment of scabies it is also used to treat crab lice infestationlyclear dermal cream should be used to cover the whole body and left on overnig