Pyriderm shampoo in the treatment of Pediculosis capitis.

112 patients with head lice were treated with a shampoo containing pyrethrins. All were treated twice with an interval of one week. At examination immediately before the second treatment, 6 patients had small, newly hatched lice, and one patient had both small and mature lice--probably due to reinfestation. This patient was lice-free after the third treatment, the other patients after the second treatment. It is concluded that pyrethrins are highly effective against head lice and have the advantages of a low toxicity to mammals and a short contact time.