A new case study reveals that few children may develop anaphylactic allergies to previously tolerated foods after blood/platelets transfusions.
"It is very unusual to identify someone who experienced passive transfer of allergy from blood products," said Julia Upton from the Hospital for Sick Children (SickKids), Toronto. "Importantly, this condition has an excellent prognosis and typically resolves within a few months," she added.
Blood donors who have food allergies can transfer immunoglobulin E, an antibody that reacts against allergens, from blood products such as platelets.
These reaction, with symptoms such as facial swelling, throat discomfort or sudden fatigue, should be treated immediately at an emergency department, said the case study published in Canadian Medical Association Journal (CMAJ).
When there is passive transfer of allergies after blood transfusion, physicians should follow up with the family after a few months to decide the timing of careful reintroduction of the temporary allergens into a child's diet, Upton said.
It is also important for physicians to report suspected cases of passive transfer of allergies to the hospital's transfusion service to investigate the cause and ensure the safety of the blood supply.