What are the differences between pyrethrin and permethrin?

See Below. Both are insecticides. Pyrethrins are naturally occurring compounds derived from the chrysanthemum plant. Permethrin is a more potent synthetic version of the naturally occurring compounds.
Lice and Scabies. Pyrethrin is used to treat lice, which are tiny insects that can infest and irritate the scalp (head lice), the pubic area (crabs), or the body. This medication works by paralyzing and killing lice. Permethrin is used to treat scabies ('mites that attach themselves to the skin) in adults and children 2 months of age and older.