While breast-feeding, Dalan said, there appears to be some benefit to the baby in terms of avoiding allergies.
"The breast milk has protective antibodies and the infant's immune system is not quite developed to the degree it can be," he said. "This is not just for allergies, but it's for anything in the baby's environment."
But once the child stops nursing, it's not clear that breast-feeding will keep a child from developing allergies.
"It could be. There's a lot of protective aspects about breast-feeding," Katial said. "There might be some benefits, but you can't say absolutely."
"It may delay onset of allergies," he added, but noted that "that one's a little more gray."
For his part, Shulan said that "I've seen a number of articles suggesting that, at least for children, there is a decrease in allergies for children who have been breast-fed."
A definitive study, however, was lacking, so until then, this seasonal allergy myth will remain a little dusty.
Allergies may start in childhood, but adults can become allergic to things they weren't previously allergic to, according to Katial.
"There's a feeling that allergies only exist in children and then persist into adulthood. But we frequently see patients that have done well most of their lives and then as an adult they do develop allergies," Katial said.
New exposures can also trigger allergic reactions that wouldn't have been experienced before. For example, moving from the West Coast to the East Coast might bring on an allergy to ragweed, which thrives in the Northeast. Or, if you did not have a pet growing up, a new dog or cat could trigger an allergy.
Sensitivity may also change, as common allergens, such as pollen, dust mites and molds, provoke more of a response.
An adult complaining of symptoms will undergo the same tests administered to allergic children.
"If an adult comes in with symptoms that are typical for seasonal allergies, they should be evaluated to see what they're sensitive to, and again, appropriately treated depending on what the allergen is and given advice regarding environmental precautions and the appropriate medications," Katial said.
"Clearly, one can develop both allergies and asthma as an adult and it doesn't have to be just in children," he said.
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