Who Gets the Most Mosquito Bites? What Really Repels Mosquitoes

It’s not your imagination — mosquitoes really do find some people tastier than others. I’ve always suspected this, and now new UK research confirms that some lucky individuals produce certain skin oils that seem to repel mosquitoes… but, while fascinating, these findings aren’t at a point where we can put them to practical use. Since it’s summer, I thought it would be good to check on the latest expert advice about what’s effective and not effective… safe and not so safe… for keeping mosquitoes away.

This is important because not only are mosquito bites uncomfortable, they also can give you diseases such as West Nile Virus and encephalitis — even here in modern-day America. Mosquito maven Susan M. Paskewitz, PhD, professor in the department of entomology at the University of Wisconsin in Madison, was happy to offer some helpful advice.

What’s In Bug Spray?

Dr. Paskewitz was reassuring about the safety of insect repellents, saying that there’s not much evidence that they are harmful. She told me that just about all the products sold today are formulated using one or more of the following substances…

• DEET. This chemical (on labels it may be called N,N-diethyl-3-methylbenzamide) was developed by the US Department of Defense after WWII for military personnel stationed in tropical climates. Dr. Paskewitz told me it has supposedly been applied to humans more than eight billion times since becoming commercially available in 1957. Between then and 2002, which is when a report on DEET safety was published in The New England Journal of Medicine, there were fewer than 50 known cases of serious adverse effects from DEET — most caused by incorrect use and most resolving with no long-term consequences. But DEET-containing products do have the potential to irritate the skin of people who are sensitive and DEET should always be kept away from the eyes. Noting that DEET doesn’t accumulate in the body, Dr. Paskewitz said that there’s no evidence that using DEET causes cancer or any other long-term health concerns.

• Picaridin. This compound (its scientific name is KBR 3023) is odorless, less oily and even less irritating to the skin and eyes than DEET, Dr. Paskewitz told me.

• IR3535. Derived from natural compounds, this is the proprietary ingredient that supposedly makes Avon’s Skin So Soft Bug Guard products and BullFrog Mosquito Coast sunblock work so well. It can be irritating if it gets in your eyes but is otherwise safe, Dr. Paskewitz told me.

• Lemon Eucalyptus Oil. An extract from the lemon eucalyptus plant, the active ingredient is para-menthane-3,8-diol, and there is a synthetic version (known as PMD) as well. The only potential issue uncovered by EPA safety tests is that it, too, can irritate the eyes.

How well do they work?Dr. Paskewitz said that all these products are equally effective when tested at 20% concentration — but noted that concentrations vary in commercial products, so check labels to compare strength.

How to use safely: Though none of these products is linked to long-term health concerns, virtually all of them can be irritating to the skin for some people and for the eyes (for practically everyone). Minimize the likelihood that this will happen by using the sprays, creams and wipes only where you need to — on exposed skin, not under clothing. When using a spray product, Dr. Paskewitz advises averting your face and avoiding your eyes (donning glasses can be helpful) and holding your breath while spraying. Wash hands after applying to prevent getting the products in your eyes if you touch your face. Avoid cuts, scratches and irritated skin… don’t get any on or near your mouth… and, after you come indoors, she advises washing all treated skin with soap and water. If you’re prone to irritation, Dr. Paskewitz suggested trying a repellent formulated to be sprayed onto clothing, such as permethrin(Bug Off and Insect Shield are two such products).

Aromatherapy — Natural Scents that Repel Mosquitos

If you prefer to take a natural approach, there are numerous plant-based oils that can be effective at keeping mosquitos away — peppermint, cinnamon, citronella, cedar, clove, lemongrass, rosemary, thyme, lavender, catnip, patchouli, tea tree oil, eucalyptus and sage, to name a few. But be careful — you’ve heard it before from me, but it bears repeating: Natural substances also have the potential for harm if used incorrectly. Essential oils, in particular, are potent and may cause liver problems in susceptible individuals.

How well do they work? These oils haven’t been tested by the EPA for this purpose, but a few smaller independent studies have found undiluted oils of citronella, patchouli, clove, catnip and Zanthoxylum limonella(lemon oil) quite helpful, sometimes offering more than two hours of potent repellent power.

How to apply:Here’s the rub: Undiluted oils provide the best protection when applied directly to exposed skin. But they can also cause irritation and rashes and haven’t been tested for safety. A good solution is to look for these oils in natural skin creams, lotions or oils that use them as ingredients, formulated to be less irritating.

What Else Works?

Preventive advice includes doing all that you can to reduce the number of mosquitoes in your environment, suggests Dr. Paskewitz. This includes taking the following measures:

• Eliminate standing water. Mosquitoes breed like crazy in ponds and other natural pools of water. To avoid bites, avoid these locations, particularly on days that are hot and still. Keep control over the mosquito population around your home by draining water anywhere that it might puddle — even in small containers such as empty flower pots, spare tires, kiddie pools, etc.
• Stay indoors at dawn and dusk. Mosquitoes are most prolific in the early morning and at twilight, so if there are lots in your area, try to stay indoors at these times.
• Watch what you wear. Mosquitoes are attracted to dark colors, particularly red and violet, so wear lighter and brighter colors — also wear long sleeves and pants.
• Don’t drink alcohol. Drinking alcohol may boost the sugar content in your sweat, making you more attractive to mosquitoes.

If you’re itching to learn more about mosquito behavior and how to stay safe from these pesky critters, visit the Integrated Mosquito Management Web site that Dr. Paskewitz and her team at the University of Wisconsin have developed: http://www.entomology.wisc.edu/mosquitosite/. It’s an interesting read — and they put lots of home remedies to the test.