By the way, doctor: Are there any good DEET-free repellents?
Q. DEET makes a mess of my fly fishing gear. I've heard there are some new mosquito repellents that don't contain DEET. Are they any good?
A. N,N-diethyl-m-toluamide — DEET for short — is the active ingredient in many major brands of mosquito repellent, such as OFF! DEET is a strong chemical that can damage plastic (including artificial fingernails), rayon, spandex, leather, and painted or varnished surfaces. People who fish must be careful to wash DEET off their hands because it can dissolve fishing line, wader material, and related gear.
Many people would prefer to use "natural" products, such as citronella or peppermint oil. Until recently, concerns about West Nile virus, a potentially deadly infection spread to humans by mosquitoes, prompted public health officials to advocate the use of DEET-containing products, because they last longer on the skin than most other repellents.