Mosquito Sprays – Safety and Efficacy, Spring/Summer 2016 Newsletter

As we look forward to the approaching warmer weather and all the upcoming summer fun, it’s also important to remain aware of one of our least favorite aspects of summer, the mosquito. In the United States, most mosquito bites are merely a temporary annoyance. However, in some cases mosquito bites can lead to systemic mosquito-borne illnesses or secondary skin infections. We’ve seen plenty of media coverage on Zika virus, but in the United States, mosquitoes are most often responsible for the spread of West Nile virus. Much more commonly, mosquito bites may cause local skin irritation and minor infection due to scratching. As is often the case, prevention is the best course of action. Fortunately, there are many mosquito and insect repellants available on the market.

For more than 50 years in the U.S., DEET has been the most well-known and widely-used insect repellant. Sprays and lotions containing DEET range in concentration from as low as 2-3% to as high as 100%. Greater concentrations afford longer periods of protection, with 20% formulations providing around 3 hours of protection and 100% DEET topping out at 12 hours of protection. Although DEET is a very effective mosquito repellant, there is some controversy surrounding higher-concentration formulations. Products containing up to 20-30% DEET are generally considered safe in individuals over two months of age. However, in some people DEET can be a skin irritant, and occasionally it may cause severe rashes. In any case, DEET should never be applied to broken or irritated skin, and should be washed off once no longer needed.

Although DEET is by far the most popular insect repellant recognized by the Centers for Disease Control, there are other recognized alternatives. Products containing picaridin, IR3535, oil of lemon eucalyptus, and para-menthane-diol are all also acceptable options according to the CDC and the EPA. All of these are also safe for use on children, but products containing oil of lemon eucalyptus should be avoided in children under age three. Unless otherwise advised by your physician, all of these products are also generally considered safe for pregnant and nursing women. Safety data for all of these products also rely upon usage according to the label with regards to frequency of application. In general, lower concentration products protect for less time and higher concentrations protect for longer periods.

Regardless of your choice of active ingredient, avoid products containing sunblock, as sunblocks generally need more frequent re-application than insect repellants. Additionally, aerosol products should never be sprayed directly on the face. Instead, spray the repellant on the fingers and apply cautiously to the face and ears. Never apply repellant under clothing. It should only be applied to exposed skin. As with any chemical product, younger children should not be allowed to handle insect repellants directly. Adult application is always preferred. Finally, never apply insect repellant to children’s fingers, as children frequently touch their mouths and eyes. In summary, approved insect repellants are generally considered safe and effective when used according to the label.