Like pollens that can spread quickly through the air, myths about seasonal allergies also seem to circulate widely.

"I hear allergy myths all the time," said Dr. John Costa, medical director of the Brigham and Women's Hospital Allergy and Clinical Immunology Practice in Boston.

To clear the air of these common misconceptions, here are nine allergy myths that may be making the rounds.

Myth: Everybody has allergies. Only one in five Americans has allergic rhinitis, which in spring is also known as "rose fever" and in fall is called "hay fever," Costa said. While there has been a rise in the incidence of seasonal and food allergies in the United States over the last 20 to 30 years, people who don't have any allergies don't really worry about getting them, he said. And they often have no clue how miserable people with seasonal allergies feel, Costa said.

Myth: If you didn't have seasonal allergies as a child, you won't develop them as an adult. The body comes in contact with new things all the time, and can become highly allergic to them at any time. There is nothing innately harmful about tree pollen, for example, but some people's immune systems look at tree pollens and say, 'I'm going to have a reaction to this,' Costa said. "If you didn't have allergies as a kid, it can happen to you as an adult," he said. "If you had them as a kid, allergies can gradually and unpredictably go away."

Myth: Eating local honey helps relieve seasonal allergy symptoms. It's true that bees collect pollen from plants, Costa said, and honey has pollens in it from the local area. But, he said, the wind-carried pollens from trees, grasses and weeds that cause seasonal allergies are very light and stay airborne for a long time. The pollen in bee honey comes from flowers, and is very heavy and falls to the ground. "They are the wrong kind of pollens for causing seasonal allergies," Costa said.

Myth: Scientists can accurately predict a bad pollen season. "Predictions about pollen seasons are disingenuous," Costa said, and he refrains from making them. For example, only when forecasters can predict a great number of dry days in a row without any rain (such as a severe drought), can pollen predictions be made. During that time, nothing is growing, so pollen can be ruled out, he explained. "Short of severe climactic change, it's hard to say anything meaningful about pollen season," Costa said.

Myth: Moving to a different geographic area could ease seasonal allergies. "Moving is of little benefit to the seasonal allergy sufferer," Costa said, because pollens are actually shared over large areas. Ragweed in New England is the same as ragweed in Texas, and people who are allergic to grass pollen may just be miserable everywhere, because this type of pollen is incredibly cross-reactive, he said. [8 Strange Signs You're Having an Allergic Reaction]

Myth: Flowers are a common trigger for seasonal allergies. "It's rare for flower pollen to contribute to seasonal allergies," Costa said. Flower pollens are relatively heavy and fall to the ground rather than lingering in the air. In contrast, pollens from trees (such as birch, oak, elm, maple and cottonwood), grasses and weeds are very light and stay airborne for a long time, he explained. "Unlike [with] tree and grass pollens, you can control your exposure to flowers," Costa said.

Myth: All nasal sprays are bad. Patients need to use some nasal sprays selectively and judiciously, Costa told Live Science. Topical nasal steroids are usually best for people with seasonal allergies, he said. They work by reducing inflammation in the lining of the nose. Most are available by prescription and can be used safely for years without worry, Costa said. One brand, Nasacort AQ, is now available over the counter.

However, the sprays can have a downside. People sometimes call over-the-counter nasal decongestant sprays addictive, Costa said, and it's true that when people use decongestant sprays for more than five days in a row, the blood vessels lining the nose can become dependent on the drugs, and rebound congestion is a common problem. To relieve the stuffiness, some may use even more nasal spray, and get caught in a vicious cycle of overuse.

Myth: You only need to take allergy medication when you start feeling terrible. Allergies are an inflammatory response, and their effects can last for weeks. "It makes more sense to use allergy medications on a consistent basis to maintain control over moderate to severe allergies," Costa explained. People should know their allergic triggers and their seasons, and then use medications regularly when those pollens are in the air, he suggested.

Myth: Allergy shots are not worthwhile. Over the last 20 years, allergy shots have become more sophisticated and fine-tuned, Costa said. The shots are typically given to people with the most severe symptoms. "In 2014, we have a much better chance of using the right dosages of allergens than we did with your grandfather's allergy shots," he said. The FDA has recently approved daily tablets that dissolve under the tongue as an alternative to allergy shots, but they are only available for ragweed or grass pollens.

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Related on MNN: How to survive the pollen season (without locking yourself inside the house)

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