Pyrethrins and Pyrethroids in Dermatology

In 1987, we reviewed the history and development of natural pyrethrins and man-made synthetic pyrethroids.1The following is a condensation of that report, an update on developments to 1989, and comments on a more recent study of permethrin 5% cream for the treatment of scabies that appears in this issue of theArchives.2 PYRETHRUM AND PYRETHRINS The insecticidal properties of flowers in the genusChrysanthemumhave been known for centuries. The earliest use was carefully guarded and remains unrecorded, but is generally considered to have originated in Persia, now Iran. George A. McLauglin,3in his eminently readable chapter on the history of pyrethrum, states that the first commercial production ofChrysanthemum cinerariaefoliumbegan in Dalmatia, now Yugoslavia, in 1840. Pyrethrum is the approved common name for the dried flowers, and the terms pyrethrum powder or pyrethrum extract are used to describe the crude products obtained from them.