DEET Dangers

Published 12:00 am Monday, July 29, 2002

The recent rash of West Nile Virus findings in Alabama has health officials urging residents to use every precaution possible to avoid being bitten by mosquitoes.

These include tips on clothing to wear when outside and items which may seem obvious, such as removing standing water that attract mosquito breeding.

Another tip which is often suggested to prevent bites is the use of repellents containing the chemical diethylmetatoluamide, or DEET.

Repellents using this chemical have widely proven to be the most effective, and the chemical was actually developed for the U.S. military in the 1940's.

These repellents usually prove most effective because they last longer against mosquitoes and other biting bugs that transmit Lyme disease than other repellents which usually contain various plant oils.

According to the West Nile Virus Information Center web site, when using products with DEET it is important to note that the chemical is absorbed readily through the skin, so it is probably best to apply these products sparingly.

Side effects which have been correlated with the use of these products include rash, swelling, itching and eye irritation, usually a result of rubbing the eyes with hands that have been sprayed. The chemical can be extremely irritating to the eyes, but not corrosive.

In some rare cases, DEET has been linked to serious complications such as slurred speech, confusion and seizures, and in most of those instances the use of the repellent was excessive.

Other adverse effects have been known to take place when the product has been used under hot, humid conditions and used on the skin areas that are in direct contact during sleep. Under these conditions, the skin can become red and tender and exhibit blistering and erosion, leaving painful weeping areas that are slow to heal. Permanent scarring can result from severe reactions.

As a precaution against certain side effects, the American Academy of Pediatrics recommends that repellents used on youngsters contain no more than 10 percent DEET. Keep the chemical out of young mouths and eyes by applying it yourself. A thin layer of the repellent should prove effective enough.

Only products containing lower concentration of the chemical should be used on children.

If headache or any kind of emotional or behavioral change occurs following the use of DEET, the use should be discontinued immediately.

The Environmental Protection Agency estimates that more than 38 percent of the U.S. population uses a DEET-based repellent each year.