Five bug repellents scored high marks for preventing bites, and another did pretty well, but four common choices didn’t make the grade in May 2010 testing by Consumer Reports. As a parent and pediatrician, I want a mosquito and tick repellent that is safe, effective, and easy to use. It also helps if it doesn’t smell like bug spray.

Insect and arachnid bites aren’t just annoying; they are also the cause of hundreds of West Nile virus infections, about 1500 cases of malaria, and about 35,000 cases of Lyme disease diagnosed in the US each year – not to mention the million people who die from malaria each year around the world. Even though most mosquito bites are just an itchy nuisance and most tick bites are barely noticed, it’s important to have a reliable way to block bites when needed.

Repellent testing involves daring testers who put their bare arms in mosquito-filled cages and who let ticks crawl on them, while observes record how long it takes the critters to start biting. The top five products prevented bites from ticks and two important species of mosquitoes for at least the full eight hours of the test. In four of these winners, the active ingredient was DEET. The other was a plant-based repellent using oil of lemon eucalyptus:

• Off Deep Woods Sportsmen II (DEET 30%)
• Cutter Backwoods Unscented (DEET 23%)
• Off FamilyCare Smooth and Dry (DEET 15%)
• 3M Ultrathon Insect Repellant 8 (DEET 25%)
• Repel (Plant Based Lemon Eucalyptus)

Another repellant scored almost as well, but the volunteers did start getting mosquito bites after 7 hours:

• Natrapel 8-Hour with Picardin (Picaridin)

All of the above repellents use active ingredients registered with the EPA and included in the CDC recommendations for preventing diseases spread by insect bites.

Other products tested had some benefit, but scored much lower overall:

• Avon Skin-So-Soft Bug Guard Plus IR3535 Expedition SPF 30 (IR3535)
• Bite Blocker Xtreme (Plant Oils)
• Cutter Skinsations Clean Fresh Scent (DEET 7%)
• Burt’s Bees All Natural Herbal (Plant Oils)

These results were similar to what my family found last summer when we tested a number of ‘natural’ insect repellents on a trip to Yosemite.  Repel was the clear winner, preventing all bites.

How safe are the top repellents?

The EPA rates DEET as Category III (slightly toxic) for acute oral or dermal exposures. DEET is irritating to the eyes and mucus membranes. Skin rashes are the most common side effect and are uncommon. Suspected serious adverse reactions are rare, but include seizures and encephalopathy in children. DEET is considered slightly toxic to birds, fish, and aquatic invertebrates. The EPA says that child safety claims on some DEET products are misleading and not allowed because concentrations lower than 30% are not known to be any safer. Because the risks are well understood, DEET is recommended by the CDC and AAP for use on babies down to 2 months old, but is not considered safe for newborns.

Likewise, the EPA considers picaridin Category III (slightly toxic) for acute oral or dermal exposures. In animal studies it caused slight to minimal liver hypertrophy, individual necrotic liver cells, chronic kidney inflammation, and slight kidney degeneration when ongoing large amounts of picaridin were applied to the skin. They found no evidence that it is an endocrine disruptor or carcinogen. It is nontoxic to birds and moderately toxic to fish.

I prefer the plant-based oil of lemon eucalyptus. No adverse effects have been found, other than eye irritation. The EPA considers it Category IV (practically non-toxic), for acute oral or dermal exposures – indeed for any route except being splashed in the eyes (so use lotion or use spray in the palm to apply to face). They’ve determined that it poses minimal or no risk to wildlife and is not harmful to the environment. The EPA assessment concludes that it is not expected to pose health risks to people, including children, pregnant women, or other sensitive populations. Nevertheless, the official recommendation is not to use it on children younger than 3 because testing has not yet been done on young children.

More infants and children are bitten by mosquitoes than by any other insect. But parents often don’t notice the bites on babies and young children because they don’t look like they do on teens and adults.

When a mosquito stabs her needlelike mouthparts through the skin of her victim, she injects her saliva, which is teeming with digestive enzymes and anticoagulants. The first time a person is bitten, there is no reaction. With subsequent bites, he or she becomes sensitized to the foreign proteins, and small, itchy, red bumps appear about 24 hours later. This is the most common reaction in young children. After many more bites, a pale, swollen hive, or “wheal,” appears, and it’s followed by the red bump 24 hours later. This is a familiar reaction among older children and adolescents.

Preventing mosquito bites is the key to preventing illnesses such as West Nile virus, which has spread throughout the continental U.S. Despite this alarming/troublesome fact, most Americans don’t wear insect repellent or put it on their children. For those who don’t use repellents because they don’t want chemicals on their skin or don’t like the smell or feel of DEET repellents, oil of lemon eucalyptus may be just the ticket.

Oil of lemon eucalyptus, a natural, plant-based repellent was recommended as mosquito protection in 2005 by the Centers for Disease Control and Prevention (CDC). It can be about as effective as DEET, but products containing oil of eucalyptus lemon may need to be applied more often than conventional insect repellents (especially those that contain a high concentration of DEET). Concentrations don’t differ in how much they work, only in how long they work. Oil of lemon eucalyptus usually lasts from two to five hours, but it should be reapplied right away if mosquitoes resume biting. Certified organic formulations are available at health food stores like Whole Foods and Wild Oats.

If your kids are ten or younger, don’t let them apply insect repellent themselves; instead, apply it to your own hands and rub them on your kids’ exposed skin, avoiding the eyes and mouth. Forgo their hands if they are often in their mouth.

Here are some additional tips for avoiding mosquitoes.

• Many species of mosquito prefer biting at dusk, early evening and dawn. It gets worse when the weather is hot or humid. Avoid playing/being outdoors during your area’s peak biting hours.
• Mosquitoes are attracted to things that remind them of mammal flesh and nectar, their two primary food sources. When outdoors, wear clothing that covers most of your body and avoid bright florals. Khaki, beige and olive hold no special allure for mosquitoes.
• However, mosquitoes are attracted to certain body odors, so be aware of the fragrances in your soaps, shampoos and lotions.
• Citronella candles may be useful when your children are playing outside.
• Help reduce the number of mosquitoes in areas where your children play by draining sources of standing water such as flowerpots, birdbaths, swimming-pool covers, buckets, barrels, old tires and clogged rain gutters.

Because West Nile virus has made preventing mosquito bites more important in the United States, and because some insecticides are toxic, people have become increasingly concerned with finding gentle and effective solutions at preventing mosquito bites. DEET is the most effective ingredient at preventing mosquito bites. It does not kill mosquitoes, but repels them, discouraging them from biting.

Although DEET is recommended for pregnant and nursing women, we do know that DEET is absorbed through the skin. It crosses the placenta in pregnant women and into the breast milk of those who are nursing. This may be worth the exposure, though, because West Nile virus infections can also cross the placenta, and may pass into breast milk.

Researchers at Chapel Hill Dermatology and the Florida Medical Entomology Laboratory tested 16 different mosquito repellants on 15 volunteers who thrust their arms into cages full of mosquitoes. Four of the products contained DEET, the others were plant-based products. The results were published in the July 4, 2002 New England Journal of Medicine. Bite Blocker for Kids, whose active ingredient is soybean oil, was the most effective of the natural products – working well for an average of 94 minutes in the cage after application. The CDC suggests soybean oil products when looking for a DEET alternative. Herbal Armor (a combination of citronella, peppermint oil, cedar oil, lemongrass oil, and geranium oil) worked well for about 19 minutes. Various Skin-So-Soft products were effective for an average of 3 to 23 minutes in a cage full of mosquitoes. Cage studies, however, may underestimate how well products work in the backyard, where mosquitoes have someplace else to go.

Enjoying pets can be a wonderful part of family life. Besides being beloved companions, pets can help children learn empathy, responsibility, and can help their immune systems learn how to minimize allergies. But since the mad cow scare in the U.S., many parents have been wondering if their pets are safe.

During the height of the mad cow outbreak in the United Kingdom, about 100 cats – about as many cats as people -contracted the disease. Many suspect that the British cats were infected by eating contaminated cat food, but this has not been proven. The risk to cats is low, but real. The sick cats should not be a risk to humans. No dogs have been reported to have become ill. The USDA, to its credit, has now moved decisively to prohibit diseased, downed, or dead cattle from entering the U.S. human food supply. However, animals not fit for human consumption might still be used for pet food. The dead animals are processed for pets in a way that is thought to prevent most diseases. I’m glad, though, that my cat likes food make from chicken and fish.

Many children are allergic to house dust. But what is it in dust that they are allergic to?

Much of dust is made up of flakes of our old skin. By itself this isn’t a problem, but as we’ve known for a while, many children are allergic to the house dust mite, a tiny creature that lives on the dust.

A significant number of children are actually allergic to mouse, cat, or cockroach allergens found in the dust, according to a  report in the December 2000 issue of the Journal of Allergy and Clinical Immunology.

When trying to get dust allergies under control, removing some of these creatures from the home might make a big difference in helping your children sleep peacefully, all snug in their beds!