Is DEET Bad? And Other Questions That Bug You.

Enjoying summer means spending time outside – which means bugs. Two bugs, in particular – mosquitoes and ticks – are cause for concern, since they can spread diseases. Here’s the scoop on summer’s most annoying pests.   

Prevention

If you’re going to be out and about, especially in wooded or grassy areas, you should dress appropriately, says Madiha Tahir, MD, of  The University of Vermont Health Network - Champlain Valley Physicians Hospital. Dr. Tahir says this means wearing long sleeves, long pants and socks. Also, choose light colors so you can spot ticks easily.

Cindy Noyes, MD, of The University of Vermont Health Network - UVM Medical Center, suggests using repellent, preferably a product containing diethyltoluamide, or DEET. It’s the most effective way of preventing mosquito and, especially, tick bites. While DEET alternatives, such as citronella and eucalyptus oil, may be somewhat effective in repelling mosquitoes, Dr. Noyes says they aren’t effective at keeping away ticks at all. Nor are wearables like treated bracelets.

“Many people worry about DEET, especially with kids,” acknowledges Dr. Tahir. “But it’s very safe if you use the products as instructed,” which includes making sure they’re not swallowed. The American Academy of Pediatrics endorses the use of DEET in children over 3 months old, as long as you don’t use it on children’s hands and wash it off when you come back inside.

DEET is an effective repellent because ticks don’t like the smell. So you have to reapply periodically to keep the odor present. “How often you have to reapply depends on the concentration of the product,” adds Dr. Tahir. “The more concentrated, the longer it lasts. For example, a product with 10% DEET needs to be reapplied every two hours, while a product with 30% DEET lasts for five hours,” she says. For more information, the EPA has a helpful website comparing different types of repellents and their time frames for reapplication. 

Dr. Tahir adds that it’s also a good idea to cover strollers and baby carriers with mosquito netting. 

Mosquito bites

While mosquitoes can transmit some viral infections, such as West Nile virus and eastern equine encephalitis, or EEE, the good news is that these are not very common, says Dr. Tahir. “The incidence of West Nile comes and goes. But as far as EEE, we’ve only seen it twice in Vermont, ever, so it’s quite rare,” she says.

A handful of malaria cases were diagnosed earlier this summer in Florida and Texas. But the risk of endemic malaria transmission in the United States remains exceedingly low, say the experts, especially in Vermont and northern New York. The Centers for Disease Control is still investigating the origin of the malaria infections in the South, but they don’t seem to be related to one another. Aside from these cases, says Dr. Noyes, all cases of malaria that have been identified in the US have been related to travel to malaria-prone areas.

So while they’re not usually dangerous, mosquito bites can be uncomfortable. They can produce redness and swelling at the site – of course, itching – and bites may be painful for kids. Dr. Tahir suggests washing the site and applying an ice pack for up to 10 minutes if you’re especially sensitive. There are also many effective over-the-counter products that reduce itching. She suggests anything containing calamine or camphor, or a low-dose steroid cream, such as cortisone. 

Tick bites: Removing a tick

If you’ve been bitten by a tick, the first thing to do is remove it. The Vermont Department of Health has some helpful instructions on how to remove a tick. Be sure not to crush it with your fingers while you’re detaching it, Dr. Tahir stresses, since doing so can transmit a Lyme or other infection just as easily as a bite. (Also keep that in mind if you’re removing ticks from your pet.) 

Instead, carefully remove the tick, then place the intact insect in alcohol or in a bag, or flush it down the toilet. 

Tick bites and Lyme: Fact vs. fiction

The thing we worry about most, when it comes to tick bites, is Lyme disease, though there are a couple of other tick-borne diseases out there, too. 

All of these diseases can be transmitted by only one type of insect: the deer tick. And, according to Dr. Noyes, Lyme doesn’t actually get passed along to the host until the tick is done feeding. So, once you remove the tick, if you notice that it’s full of blood, you should still call your primary care doctor. He or she can prescribe a one-time dose of the antibiotic doxycycline, which is very effective at preventing Lyme infection if it’s given within 72 hours. 

The telltale symptom of Lyme disease is a rapidly expanding circular rash, which usually shows up within seven to 10 days if it’s going to appear, Dr. Noyes says. She notes that people can also experience contact dermatitis from a tick bite, which is very different from a Lyme rash and not a cause for concern. 

However, she says, not all people who are bitten by a Lyme-infested deer tick will react the same way. Some people won’t have any symptoms, not even the rash, while others say they feel like they’re coming down with the flu. Symptoms often go away without treatment, but some people can have complications, including facial weakness, nerve irritation, meningitis, or a type of heart inflammation called Lyme carditis. While those complications aren’t very common, they’re the reason doctors recommend seeking treatment if you’ve been exposed. 

There is a blood test for Lyme disease, and doctors will usually order it after an exposure. However, because it’s an antibody test, a positive result won’t usually show up until several weeks after the onset of symptoms. For this reason, the symptoms are more helpful for getting started on an effective treatment regimen. 

“If you have symptoms and a rash, your Lyme test may be negative, but we would still treat you,” says Dr. Noyes. “On the other hand, people can have a positive Lyme antibody test and not have an active Lyme infection.” This could be related to false positive testing, or a past history of infection.

A couple of myths relating to Lyme disease worth debunking:  First, if you’ve been infected, you can absolutely get it again, since Lyme antibodies wane over time. Also, if someone contracts Lyme disease, that doesn’t mean they have some kind of immune deficiency. “Lyme disease has to do with exposure, and it’s not an indicator that your body is deficient in any way,” Dr. Noyes says. 

Other tick-borne diseases

So, what about those other tick-borne illnesses we mentioned earlier? 

According to Dr. Tahir, the deer tick can also transmit anaplasma and ehrlichia, types of bacteria that can make people sick. Symptoms of ehrlichiosis includes fever and chills, nausea and vomiting, and confusion. If a rash appears – which doesn’t always happen, and is more common in children than in adults – it looks quite different than a Lyme rash, and would show up as red dots or splotches rather than a bullseye pattern. Anaplasmosis presents with similar symptoms, but no rash. 

Like Lyme disease, those infections can also be detected through blood tests, but the tests for those three infections – Lyme, ehrlichiosis and anaplasmosis – are all different. Treatment, however, is the same for all three: a course of antibiotics, usually doxycycline.

Bottom line? The best way to deal with ticks, mosquitoes and other summer bugs is by keeping them off of your skin in the first place. Wear the proper clothing and use repellent, say the experts, and you’ll go a long way toward protecting yourself.