Choosing a Mosquito Repellent

Mosquitoes are more than an annoyance; the tiny insects are actually dangerous. Mosquitoes are responsible for the transmission of a number of diseases including malaria, dengue, West Nile, Zika and encephalitis. Mosquito repellents help protect against bites and disease spread.

There are an estimated 3000 species of mosquitoes and approximately 85 species have been identified in Texas. Male mosquitoes feed on nectar and plant juices, while female mosquitoes require blood protein to produce eggs. After puncturing the skin, the female mosquito injects a small amount of saliva into the wound to prevent the blood from clotting as she draws it. The itching and red bumps triggered by bites are due to the saliva.

To reduce the risk of mosquito bites, experts recommend keeping areas free of food, water and shelter for the insects. This includes draining standing water where mosquitoes breed, using mosquito fish, applying screens to windows and avoiding areas where mosquitoes are likely to gather.

Wearing light-colored, protective clothing and using mosquito repellents and insecticides are also helpful in preventing mosquito bites.

Most mosquito repellents contain one of these common ingredients:

• DEET –one of the most common, most effective repellents, DEET has been deemed safe for use in a 20-50 percent concentration. The higher the concentration, the longer the product remains effective on the skin. Intense doses can lead to neurological damage, but deemed safe when used as directed. Can damage plastics, leather and synthetic fabrics
• Picaridin –similar in efficacy to DEET, but evaporates from the skin more slowly than DEET, so may be effective longer. Odorless, not greasy and does not damage plastics
• IR3535 –some studies show formulations of 10-30 percent effective at repelling biting insects, while other studies found the product less effective than DEET. Does damage plastics. Products combining sunscreen and IR3535 are not recommended since frequent reapplication needed for adequate sun protection could result in over-exposure to the repellent
• Oil of lemon eucalyptus – botanically based insect repellent, not recommended when risk of West Nile virus is high. Low toxicity, but can irritate eyes. Has not been thoroughly tested for use in children under the age of 3

If you need help in choosing a mosquito repellent, ask your dermatologist for information about the safest most effective products available.