It may be possible for people to have allergic reactions to antibiotic residues in foods such as fruits and vegetables.

Researchers looked at the case of a 10-year-old girl who had an anaphylactic (severely allergic) reaction after eating blueberry pie, the American College of Allergy, Asthma and Immunology (ACAAI) reported. The patient had a medical history of asthma and seasonal allergies as well as anaphylaxis to penicillin and cow's milk; she was not known to be allergic to the ingredients in the pie that triggered the reaction.

After weeks of testing both the patient and the pie the researchers determined a streptomycin-contaminated blueberry most likely caused the reaction. Streptomycin is sometimes used as a medicine to fight disease, but is also used as a pesticide to slow the growth of bacteria, fungi, and algae on fruit.

"As far as we know, this is the first report that links an allergic reaction to fruits treated with antibiotic pesticides," said allergist Anne Des Roches, MD,FRCP, lead study author. "Certain European countries ban the use of antibiotics for growing foods, but the United States and Canada still allow them for agricultural purposes."

New regulations from the U.S. Food and Drug Administration (FDA) could help reduce these antibiotic contaminants in food, which could also help combat the pressing problem of antibiotic resistant bacteria.

"This is a very rare allergic reaction" said allergist James Sublett, MD, ACAAI president-elect. "Nevertheless, it's something allergists need to be aware of and that emergency room personnel may need to know about in order to help determine where anaphylactic reactions may arise. Anyone who is at risk for a life-threatening allergic reaction should always carry epinephrine. They also need to know how to use their epinephrine in an emergency situation."

The findings were published in the September issue of Annals of Allergy, Asthma and Immunology.