What is Lyclear Dermal Cream Permethrin 5% W/W used for? Lyclear Dermal Cream 30g is used to treat infestations of scabies and crab lice on the body. It contains the ingredient permethrin which belongs to a group of medicines called pyrethroids which kill mites such as scabies and crab lice. You must talk to a doctor if the symptoms worsen or do not improve