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Our Friend DEET

For many, DEET is a four letter word and it is something to be avoided at all costs. But short of staying inside, DEET (N,N-Diethyl-meta-toluamide) is our best defense against the biting insects of summer because it masks the scent of CO2 and confuses mosquitoes.

DEET is overwhelmingly considered safe, however, there are varying recommendations for DEET content in bug sprays for certain populations.

The American Association of Pediatrics recommends avoiding DEET containing products on infants 2 months or younger and using a bug repellent containing 10 percent DEET for children older than 2 months.

Pregnant Women
Pregnant women should use bug repellents containing 30 percent or less of DEET because avoiding mosquito transmitted diseases outweighs the minimal risks.

DEET for the Rest of Us
For adult men and women, look for a repellant containing up to 50 percent DEET.  (There are no additional benefits in using a product that has a percentage of DEET higher than 50.)

DEET percentage is not a measure of strength.  It is a measure of how long the product is effective.  A product containing 10 percent DEET needs to be reapplied in 1 to 2 hours, while a product containing 50 percent DEET needs to be reapplied in 4-5 hours.

Additionally, the efficacy of a DEET containing product is impacted by heat and water.  If you are sweating or swimming, you need to apply it more often.  Finally, avoid products that contain both bug repellant and sunscreen because DEET-containing bug repellent can negatively impact the efficacy of sunscreen.

Michele Casey, MD, is the director of Primary Care for WakeMed Physician Practices and a Primary Care Physician atWake Specialty Physicians -Falls Pointe Medical Group