BOSTON (CBS) – More children are appearing to have allergic reactions to fruits and vegetables, but this has nothing to do with the food.

Farmers often use antibiotics to keep pests away and that’s a problem for some children.

A case highlighted in the Annals of Allergy, Asthma, and Immunology explained how a 10-year-old suffered a life threatening reaction after eating blueberry pie.

The girl had a history of asthma, seasonal allergies, and allergies to milk and penicillin. None of the ingredients in the pie were triggers for her.

It turns out the problem was the antibiotic streptomycin. The blueberries had been treated with this drug to keep bacteria, fungi, and algae from growing on the fruit.

Dr. James DeAngelo, an allergy specialist said, “This could explain why so many people insist they’re allergic to berries, but when we test them to berries, they’re negative, and then they re-consume berries, they seem to tolerate them.” He added that true allergies to any kind of berry are extremely rare.

Doctors think traces of streptomycin on produce, meat, and in the water supply could have played a role in the girl’s reaction.

Dr. DeAngelo added, “One batch of blueberries may contain a high amount of streptomycin, whereas another may not. She already had what I call sensitivity to things in general, so was more prone.”

Countries in Europe are prohibited from using antibiotics on food, but it is allowed here and in Canada. This girl’s reaction is rare, but specialists in this field hope to raise awareness as allergic incidents continue to rise.