Last weekend, a man murdered a pastor conducting a church service. Family members say he suffered mental illness after contracting Lyme Disease. Which is more harmful: the risk of infection from an insect bite or the potential health effects of the ingredients that make insecticides work? Here's the bottom line.
Insecticides prevent bug bites and protect kids from serious illnesses like Lyme disease and West Nile Virus--but there are still many who question its safety. What is more harmful: the risk of infection from an insect bite or the potential health effects of the ingredients that make insecticides work?
The most commonly used insect repellant is DEET (its actual name is N,N-Diethylmetatoluamide). It protects against bites from mosquitoes, ticks, and biting flies. The AAP has published recommendations about the strength of DEET that can safely be used on children. Initially, the AAP advised using 10% DEET or less, and only on children over the age of 2 months. Recently, there have been published statements suggesting that up to 30% DEET is safe for children. While it is still not recommended for infants under eight weeks, it is considered safe for pregnant women. Keep reading below.
DEET is a chemical that has been shown to have some adverse effects in humans. The most common is a local skin reaction where the DEET is applied. Itching, burning, or redness of the skin can occur anytime anything is applied to the skin. In the case of DEET, the likelihood of irritation is a bit higher than average. DEET is designed for use on the skin but not on clothing. In fact, it can change the consistency of certain types of plastics, effectively dissolving them.
But the bigger concern about DEET is an association with seizures. There have been 10 reported cases of seizures in children after the application of DEET, with the last one reported in 1992. In its most recent statement, the EPA argues that there are an estimated 90 million DEET users in this country, but the risk of seizure among DEET users is only one in 100 million.
In 2005, the AAP published a list of alternatives to DEET that are considered safe for children. The list includes Picaridin (5% or 10%), oil of lemon eucalyptus, and 2% soybean oil.
â€¢ Picaridin (5% or 10%) is considered the most effective alternative to DEET. It was first made publicly available in 1998 and was registered with the EPA in 2001. It has been aggressively studied over the past decade and most reports demonstrate that it has the same safety profile as DEET--while being a little less irritating to the skin. Picaridin also doesn't dissolve plastics the way that DEET does. However, compared to DEET--with its 60-plus year history of data--Picaridin is a newcomer. Picaridin also has not been proven to be effective against tick bites; its proven utility is really against mosquitoes and biting flies. Until it is shown to be effective against ticks, certain diseases--like Lyme disease--are better prevented using DEET. All of the safety data on Picaridin looks promising thus far, but often it is only time that tells.
â€¢ Oil of lemon eucalyptus (20%) is made from eucalyptus leaves and twigs. The natural oil repels mosquitoes and biting flies. Safety studies suggest that the only adverse effect is eye irritation. Many consumers like oil of lemon eucalyptus for its name--it is a "natural" product rather than being a chemical or drug. The CDC has endorsed it as well, suggesting that it can be used to protect against West Nile virus in lieu of DEET or Picaridin. Oil of lemon eucalyptus has been on the market since 2000, so like Picaridin it's a relative newcomer. It has also not been studied in children under age 3 years, and therefore cannot be recommended for them.
â€¢ Soybean oil (2%) was endorsed by the EPA as a reasonable mosquito repellant, though it is less effective than DEET, Picaridin, and oil of lemon eucalyptus. However, a study published in the New England Journal of Medicine in 2002 concluded that because it only works for approximately 94 minutes, it does not provide sufficient protection against mosquito bites and mosquito-bourne illnesses.
â€¢ Citronella is found in candles as well as oils for topical use. The main problem with citronella is that while it works, it works for even shorter durations than soybean oil. One recent study demonstrated that it only remained effective for 20 minutes. It has not been studied in children under 2 years.
â€¢ Lavender is also used as an insect repellent, but data shows that it is effective for about half an hour. It hasn't been studied in children under two years, either. Among children with sensitive skin, lavender is a well-regarded irritant.
Overall, synthetic repellants such as DEET and Picaridin are more effective than their natural counterparts--they last longer and work better.
For Dr. Cara's bottom line, go to page two.
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|Dr. Cara Natterson, a graduate of Harvard University and the Johns Hopkins School of Medicine, and author of "Your Toddler: Head To Toe," is a pediatrician and mother of 2. She is working on her forthcoming book, "Dangerous or Safe?"|