Are You a Mosquito Magnet?
Experts try to crack the code behind why mosquitoes like some people more than others. Plus, tips on keeping mosquitoes at bay and the best mosquito repellents.
Keeping the Bite at Bay: Chemical-Based Mosquito Repellents
Plenty of mosquito repellents line the shelves of drugstores and supermarkets each summer, but they're not all created equally.The majority of available mosquito repellents derive their effectiveness from chemicals. Protecting the public from mosquitoes since 1957, DEET continues to be the chemical of choice used in repellents. In repeated studies, it's been proven the most effective chemical repellent on the market. Repellents with 23.8% DEET (most formulas contain between 10% and 30%) protect wearers for about five hours, according to a study led by Mark Fradin, PhD, a researcher with Chapel Hill Dermatology.
Just how safe is it to coat yourself in DEET to keep from getting bitten by mosquitoes? "[DEET] has been in use for over 40 years and has a remarkable safety record. Only few hospitalizations have been reported, mainly due to gross overuse," Conlon tells WebMD. The American Academy of Pediatrics states that low concentrations of DEET (10% or less) are safe to use on infants over 2 months old.
DEET, though the most well-known, isn’t the only chemical used in mosquito repellents.
In 2005, the CDC began recommending alternatives to DEET for repelling mosquitoes. Picaridin, fairly new to the U.S., has been used worldwide since 1998. Marketed as Cutter Advanced, picaridin has proven to be as effective as DEET but is said to be more pleasant to use because it is odorless and contains a light, clean feel. Picaridin is safe for children older than 2 months.
The chemical IR3535, better known as Avon's Skin-So-Soft, also has been marketed as a mosquito repellent in the U.S. in recent years. To date, research shows it's much less effective than DEET.
Then there’s metofluthrin. This new chemical, approved by the EPA in 2006 as a mosquito repellent, “is selling like hotcakes,” Conlon tells WebMD. Sold as DeckMate Mosquito Repellent, it’s available in two forms. As a paper strip, you place it in outdoor areas like patios and decks. You can also wear it. As a personal repellent product, it comes in a small container with a replaceable cartridge. Clipped onto a belt or clothing, it relies on a battery-powered fan to release the mosquito repellent into the area, surrounding and protecting the wearer. It is not applied to the skin.
Alternatives to Chemical-based Mosquito Repellents
If you want to avoid chemical-based repellents altogether, a few promising alternatives do exist.
"Of the products we tested, the soybean oil-based repellent was able to protect from mosquito bites for about 1.5 hours," Fradin reports. He and fellow researchers found other oils -- citronella, cedar, peppermint, lemongrass, and geranium -- provide short-lived protection at best.
Oil of eucalyptus products, however, may offer longer-lasting protection, preliminary studies show. Endorsed by the CDC, oil of lemon eucalyptus is available under the Repel brand name and offers protection similar to low concentrations of DEET. Lemon eucalyptus is safe for children older than 3 years.
In the last few years, nonchemical repellents worn as skin patches and containing thiamine (vitamin B1) have arrived in some big-box stores under the name Don’t Bite Me! The science behind this repellent comes from a study done in the 1960s. It showed that thiamine (B1) produces a skin odor female mosquitoes don't like. But no other studies have confirmed thiamine's effectiveness as a mosquito repellent when worn on the skin. Chari Kauffmann, president of the company that sells skin patch called Don’t Bite Me!, says studies on the product are ongoing, though the company has no conclusions to report.