TRENTON, Ontario
Children who receive blood transfusions can develop new and potentially deadly food allergies, Canadian doctors warned Tuesday.
In a report in the Canadian Medical Association Journal, doctors at the Hospital for Sick Children in Toronto said an 8-year-old boy who received blood during his treatment for brain cancer showed a severe reaction 10 minutes after eating salmon.
The boy had ingested salmon often in the past with no allergic reaction. The reaction occurred after his third treatment and symptoms included swollen lips, reddening of the skin, throat discomfort and fatigue.
Shortly after eating peanuts four days later, the same symptoms occurred. Again, the boy had no previous reaction to peanuts before the blood transfusions.
The boy recovered and was given a temporary allergen prescription as a precaution.
“It’s rare to have an allergic reaction to a previously tolerated food,” Dr. Julia Upton, a staff physician in the hospital’s clinical immunology and allergy department, told the Canadian Broadcasting Company. “It’s extremely rare to have a new allergy come from a blood product.”
Doctors said that while it is a rare occurrence, blood donors who have food allergies may transfer an antibody to someone receiving a transfusion. The antibody can result in food allergy reactions.
Researchers said doctors should be aware of the possibility and if allergies occur after blood transfusions, potential donors should be screened to ensure they are suitable donors. Such incidents are called “passive transfer of allergies” from donor to patient through blood.
Doctors suggest physicians exercise precaution and after a few months check with pediatric patients who have received transfusions to see if a temporary allergen should be added to their diet.
In the boy’s case, the family reintroduced him to salmon and peanuts six months after the allergic incidents and he showed no ill effects.
“Repeat skin testing was not performed because there was no longer a suspicion of allergy,” the report stated.
“This condition has an excellent prognosis and typically resolves within a few months,” Upton said in a statement.
The medical website MedicalXpress said physicians should report suspected cases of passive transfer of allergies to “ensure the safety of the country’s blood supply.”
