I don't know about where you live, but here in Indianapolis, it felt like summer was never going to arrive. But now that it has, it's time to rejoice in the fact that consistent warm weather is finally here and bust some myths about summer. This is Healthcare Triage.

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Myth: If you get stung by a bee, you have to scrape, not squeeze out the stinger.

When a bee stings you, the stinger can break off. But it can continue to pump out venom, so it's important to get it out since more venom equals a worse reaction. Some people believe that pinching the stinger squeezes the venom sack and effectively gives you a bigger dose of venom.

To the research!

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A study published by UC Riverside and Penn State University, published in The Lancet in 1996, settled this topic. They got volunteers to allow themselves to be stung, and then removed the stinger from immediately to eight seconds later.

By the way, who signs up for studies like this? They should do a study on that.

Anyway, they removed the stinger in one of two ways. They either scraped it out or pinched it out, and then they had another person, who didn't know what method that was used, rate the wheel. There was no difference between the two methods.

However, time did matter. Substantial amounts of venom appeared to be delivered in only five to ten seconds. So the take-home message is, don't waste time looking for something to scrape with. Get the stinger out.


Myth: If you get stung by a jellyfish, you should have someone urinate on the sting.

Turns out, there's a lot of research on jellyfish stings, much of it from Australia. If you're stung by a Portuguese man of war, a randomized controlled trial published in 2006 in the Medical Journal of Australia showed that putting the sting in hot water - hot as you can stand - may actually reduce the pain. Contrary to what many people advise, putting ice on it did not.

Other people have recommended using vinegar, because it's been shown in some laboratory studies to keep jellyfish stingers from firing. However, it did nothing for those that have already fired. You'll get no pain relief. Even worse, for some jellyfish, cause different jellyfish exist in different parts of the world, vinegar makes things worse. It's really only recommended for tropical jellyfish stings.

All other remedies, including urine, are unstudied. However, there's no good reason to think that urine would be good. In fact, it dilutes the salt water around the stingers, and may cause more of them to fire. Plus, ewww. Don't do it.


Myth: It's unsafe to eat foods with mayonnaise at summer picnics.

In 2000, a very comprehensive review was published in the Journal of Food Protection looking at all reports and studies on illness and death caused by food pathogens in commercially prepared, or store bought, mayonnaise. There was none.

See, mayo, gets a bad rap because when people used to make it at home, back in "oldy times", they used raw eggs, which can contain salmonella. That would be bad. But commercial mayonnaise is pasteurized and sterile. You're much more likely to get sick from unwashed fruit or vegetables, or under-cooked meat than you are from mayo you bought at a store.

Of course, avoid foods that have been out of the refrigerator for two hours or more. Less if it's really hot out. But don't fear mayo specifically.


Myth: Citronella candles effectively repel mosquitoes.

Citronella is a natural or herbal repellent. The candles don't really work that well. A study in the Journal of the American Mosquito Control Association tested citronella candles against plain old candles. They found that those within a few feet of the citronella candles had about 42% fewer bites than those without them. However, those near regular candles had 23% fewer bites.

Get any further away, which almost all of us will be, and you have almost no protection.

This is a reduction in numbers of bites. You will still get bit. That pales in comparison to DEET, which offers complete, universal protection, like 100%, for 5 hours at usual concentrations.


Myth: You can catch poison ivy from someone else who has it.

Poison ivy creates a horrible, itchy rash that oozes across your skin and makes you miserable. When people see the rash on other people's arms, they avoid them as though they have the plague. But how contagious is poison ivy? Can you really catch it from someone else?

The oil, called "urushiol", from the poison ivy plant, is indeed incredibly contagious. If that oil is still on your clothes or on your skin or anything else, someone who touches it can get the rash too. Even after the oil dries, it can still make your skin react.

But once that oil is washed off, you aren't contagious anymore. No matter how bad your rash looks or spreads or oozes, the rash itself is not contagious. And it's normal for the rash to keep spreading even days after your contact with the plant. This is a delayed reaction from your initial contact with the oil.

It's normal for the rash to appear 24 or 48 hours after contact with plant oils. How bad the rash gets depends on the sensitivity of the skin and the oil's concentration. Scratching the blisters won't spread the rash. The fluid in the blisters won't spread the rash. You cannot spread poison ivy from one part of your body through anything but the oil itself.

However, even dead poison ivy can contain active oil for a long time. And that will give you a rash. Wearing clothing doesn't necessarily protect you because the oil can stick to clothes and you might rub up against it at a later time.

Myth: You have to wait an hour after eating before you can go swimming safely.

This one had to have been invented by adults who just didn't want to supervise swimming kids right after lunch. Regardless, there seems to be a genuine fear that if you so much stick a foot in the water while food is in your belly, you could be gripped with horrible cramps that would lead to your drowning.

There's no proof to back up this claim. In our searches of the medical literature, and in searches of other investigating this claim, we can't find any cases of drownings or near drownings attributed to eating. While that doesn't mean it could never happen, there's no proof that this is a real danger.

Expert groups don't really say that you have to wait to go swimming either. Neither the American Academy of Pediatrics nor the American Red Cross has any recommendations at all about how much you should wait after eating to swim.

How would this work, anyway? Is it because you'll get horrible cramps because your body is so busy trying to digest the food in your stomach? Look, it's true that some of your circulating goes away from your muscles and towards your gut when you've eaten, but it's certainly not enough to cause any big differences.

And, as with any exercises immediately after eating, you might feel somewhat uncomfortable after a big meal, but even if you did get some cramps, it's very unlikely that you'd be completely incapacitated. And if you get a cramp, just get out of the water, and give your body a rest.

Whether you've been wolfing down sandwiches or not, you shouldn't be swimming anywhere from which you have no ability to escape if your body is tired or has a muscle cramp or two. Making sure that you or your children only swim in safe places should keep you safe, even if you're the unlucky person who gets a cramp.