Archives October 2023

If you spend time outdoors — which we all should do, for all sorts of reasons — you are likely to encounter biting bugs. Most of the time the bites are just a nuisance. But besides the fact that sometimes they can be painful or itchy, bug bites can lead to illness — like Lyme disease from ticks, or Zika, malaria, or West Nile disease from mosquitoes. So preventing bites is a good idea for all of us, and certainly for children.

Simple precautions will help

Before talking about insect repellents, it’s important to remember that there are simple and effective precautions, nearly all of which don’t involve any chemicals. For example:

• Empty out any standing water outside your home. That’s where mosquitoes breed.
• Wear long-sleeved shirts and long pants if you are going to be in areas with lots of biting insects. If you treat clothes (and shoes and gear) with 0.5% permethrin, it can be helpful.
• Be aware that mosquitoes are most likely to be out at dusk and dawn, and plan activities accordingly.
• To avoid tick bites, avoid wooded and brushy areas and keep to the center of paths when you hike. Be sure to do a tick check when you come home — not just of all the people in your group, but also any pets or gear that came along. Taking a shower soon after arriving home can help with both tick checks and washing off any unattached ticks.

Make choices about insect repellent

Insect repellents can be very useful. Some are more effective than others, and some can have side effects, so it’s important to do your homework. The Environmental Protection Agency has a great interactive tool that can help you choose the best repellent for your particular situation.

The most effective repellent is DEET (N, N-diethyl-meta-toluamide). It works against both mosquitoes and ticks, and is definitely the go-to repellent if you really want or need to prevent bites. The higher the concentration, the longer it lasts: 10% will give you about two hours of coverage, while 30% can protect you for about five hours. The American Academy of Pediatrics (AAP) recommends not using more than 30% on kids, and not using any repellents on infants less than 2 months old.

The most common side effect is skin irritation, and if you ingest it (you never know with little kids) it can lead to nausea and vomiting. Eye irritation is possible, which is why you should never spray any repellent directly to the face, but rather put it on your hands and then carefully apply to the face. In very rare cases, like one in every 100 million users, DEET can lead to brain problems such as seizures if used in high doses. This is an incredibly rare side effect, and not something that should stop you from using it, especially if you are in an area with a lot of ticks, or an area with lots of disease-carrying mosquitoes.

Here are some alternatives with minimal to no side effects (eye irritation most common; avoid as noted above):

• oil of lemon eucalyptus, or PMD (the manmade alternative). This works nearly as well as DEET.
• picaridin, which works better against mosquitoes than ticks
• 2-undecanone
• IR-3535, the active ingredient in Avon products, although it is not very effective
• citronella, although it is even less effective.

Applying insect repellent — and sunscreen

Whatever you use, follow label directions and be sure that you are careful as you apply it to all exposed skin. It’s best to spray in an open area — and spray clothing too. Pump bottles and wipes with insect repellent may help you apply products carefully. Try to choose the best product for your situation so that you can apply it just once; the EPA tool is great for that. Don’t forget sunscreen; apply that first so your skin can absorb it.

The Centers for Disease Control and Prevention (CDC) has more information about applying insect repellent on children and preventing bites from mosquitoes and ticks.

Also visit the Harvard Health Publishing Lyme Wellness Initiative to learn about preventing –– or living with –– Lyme disease and other tick-borne illnesses.

About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD

Each year, more than 4.5 million dog bites occur in the United States. Despite what you might assume, most of these incidents don’t happen when an unfamiliar dog attacks someone in a park or another outdoor location. Instead, most dog bites are inflicted by a pet dog in a home.

Here’s advice for avoiding these upsetting and potentially serious injuries — and the steps you should take if you sustain a dog bite.

Why do dog bites happen?

Some dog bites happen by accident when people wrestle or play tug-of-war with their dog. But most of the time, dogs bite people as a reaction to feeling stressed, threatened, scared, or startled, according to the American Veterinary Medical Association (AVMA). More than half of dog bites occur in children, and they’re far more likely to be seriously injured than adults.

“People don’t always heed the behavioral signals that a dog is uncomfortable,” says Dr. Christopher Baugh, associate professor of emergency medicine at Harvard Medical School. For example, some dogs are highly territorial and will bark, growl, snap, and lunge if outsiders enter their space — whether that’s an apartment, yard, or crate. Or dogs may exhibit resource guarding, which shows up as anxious, aggressive behavior around food, toys, or beds.

“These situations can be high-risk, and children in particular have less awareness of that risk,” says Dr. Baugh, who has children and two mixed-breed rescue dogs, Harley and Roxi.

What can you do to prevent dog bites?

Any dog — even a sweet, cuddly dog — can bite if provoked, according to the AVMA. Never leave young children alone with a dog without adult supervision. And teach children to never disturb a dog while it’s eating, sleeping, or caring for puppies.

In a study of 321 facial dog bites treated at Harvard-affiliated Massachusetts General Hospital over a 20-year period, 88% of the bites were from known dogs. Most were in adults and occurred after playing with the dog, feeding the dog, and placing their face close to the dog. However, the hand (usually a person’s dominant hand) is probably the most common location for a dog bite in an adult, says Dr. Baugh.

Other tips from the CDC to prevent dog bites include the following:

• Always ask a dog’s owner if it’s okay to pet their dog, even if the dog appears friendly.
• Make sure the dog sees and sniffs you before reaching out to pet it.
• Don’t pet a dog that seems to be hiding, scared, sick, or angry.

What if an unfamiliar dog approaches you? Remain calm and still, avoiding eye contact with the dog. Stand with the side of your body facing the dog and say “no” or “go home” in firm, deep voice. Wait for the dog to retreat or move yourself slowly away.

What should you do if you’re bitten by a dog?

Clean the wound with mild soap and running water, then cover it with a clean bandage or cloth. Some online resources recommend applying an antibiotic ointment or cream. But these products are recommended only for people with clear evidence of an infection, such as redness, pus, pain, swelling, or warmth, according to the American Academy of Dermatology.

If the injury is serious — with a bite on the face, heavy bleeding, or a possible broken bone — go to the emergency room. That’s also a good idea if you’re bitten by an unknown or stray dog, in the rare event that you might need medicines to prevent rabies (rabies post-exposure prophylaxis).

“Often, people are shocked after being bit and will understandably focus all their attention on their wound,” says Dr. Baugh. The dog’s owner may check in to see if you’re okay, but then walk away. But you should get the person’s contact information and make sure the dog is vaccinated against rabies, he says.

Keep in mind that:

• Emergency rooms are often crowded with long waits, so an urgent care clinic is a good option if the injury doesn’t require immediate attention.
• Some wounds require stitches, ideally within 12 to 24 hours.
• The doctor may prescribe antibiotics to prevent possible infections, especially if you have health problems such as a weakened immune system or diabetes.
• You may also need a tetanus booster if you haven’t had one in the past 10 years. If your vaccine history isn’t available or you can’t remember, you’ll get a tetanus booster just in case.

What if a dog bite is less serious?

Let’s say you have a less serious bite from a family dog known to have a current rabies vaccine. Bites that don’t require stitches can be cleaned with mild soap and running water, then evaluated by your regular health care provider. They may tell you to simply monitor the wound for signs of infection.

“Doctors are trying to be more thoughtful about prescribing antibiotics and limit their use in low-risk situations, because overuse contributes to antibiotic resistance and exposes people to potential side effects without any benefit,” says Dr. Baugh.

About the Author

Julie Corliss, Executive Editor, Harvard Heart Letter

Julie Corliss is the executive editor of the Harvard Heart Letter. Before working at Harvard, she was a medical writer and editor at HealthNews, a consumer newsletter affiliated with The New England Journal of Medicine. She … See Full Bio View all posts by Julie Corliss

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD