An 8-year-old boy developed fish and peanut allergies after receiving blood from a donor who happened to have those severe food allergies.
Dr. Julia Upton, study lead author and the boy's allergist from the Hospital for Sick Children in Toronto, Canada, described the incident as a rare case. She explained that donors can really pass their allergies during blood transfusion because their platelets contain the allergy-triggering antibody called immunoglobulin E (IgE).
The family found out that the boy had passive allergies, two weeks after the blood transfusion, after eating salmon and peanut butter. The boy was rushed to the emergency room after having serious allergic reactions. His lips were swollen, his face was red, and he had shortness of breath and low blood pressure.
"Right away, we wondered what has happening that was different," Dr. Upton told ABC News. "Why would he all the sudden react to a food that he clearly has eaten for years?"
The doctors clarified that patients should not be worried too much because the allergies are not permanent. On the boy's case, the allergies lasted for only a few months. They had to monitor and treat him with antihistamines until his blood tested negative of the antibodies.
"Over time, since [the boy's] own immune system did not replenish the food-specific IgE, he 'outgrew' the allergy," Dr. Sherry Fazan, an allergist and immunologist at North Shore-LIJ Health System in Great Neck, N.Y, told HealthDay News. She wasn't part of the study.
Doctors explained that the blood products are usually pooled so there could be more than one donor for each bag. Thus, the boy's case is extremely rare. They were able to trace the donor of the blood and prohibited him from making any future blood donations, according to LiveScience.
The boy can now eat anything he wants without having any allergic reaction.
"He eats everything now," Upton said. "The last time I spoke to him with the family about this case was around 6 months ago, and his mom told me everything was great."
The study was published in the April 7 issue of the Canadian Medical Association Journal.
