Adult-Onset Allergies: Who’s More Likely to React – and Severely

in Fish & Shellfish

Bryce 2.largerDr. Paul Bryce
The older a patient is when diagnosed with food allergies, the more likely that person is to have a severe reaction, according to findings by Northwestern University researchers.

“We don’t know whether it’s that the actual reactions that the older individuals are having are more severe or whether some of the diseases that begin to show as people age, such as blood pressure problems or cardiovascular disease, are influencing the decision to go to the emergency room,” says Dr. Paul Bryce, one of the main study authors.

Food allergies affect an estimated 5 percent of adults, compared to 8 percent of children, and these rates are rising. The current understanding of food allergies is largely derived from studies based on children and infants, says Bryce. This leaves a knowledge gap when it comes to adults and why some allergies can develop later in life – a gap that the study, published in the Journal of Allergy and Clinical Immunology, aimed to begin to address.

Researchers reviewed 1,111 Northwestern University medical records of adult patients with food allergies and found that at least 15 percent of these patients were diagnosed with IgE-based food allergies when they were over the age of 18. Other findings:

  • Most patients had their first adult-onset reaction in their early 30s.
  • While in children more boys than girls have food allergies, more women than men have adult allergies.
  • The most common triggers were: shellfish and tree nuts. However, all top allergens that are seen in children were observed in adults. (Even adult-onset milk allergy.)

Adult Onset Allergies: Losing Tolerance

“With children, there’s a thinking that it may be that children have failed to develop a tolerance to the foods that they’re encountering early in life,” says Bryce. “But with these adults, we think that this is something very different. That they’re losing tolerance to foods that they’ve already been able to be exposed to and to eat. That may be an important difference in understanding how food allergy develops rather than how tolerance is not occurring in children.”

So why do some people lose tolerance as they get older? Why does age increase the severity of reactions? These are questions that Bryce and his team still do not have answers to, but he does say that their study provides important insight for the treatment of allergic adults.

“The allergists who are seeing these adults should be aware of the spectrum of foods that they may be allergic to, this concept of risk for more severe reactions as people are older, and just really understanding that these are likely to be true food allergies even though they may be against some of the foods that are typically seen in children,” he says.

According to Bryce, these findings are an early indication of the characteristics of adult-onset food allergies, but there needs to be further investigation.

Related Reading:
Study Finds Doubling of Adult Food Allergies: 5 Takeaways

Shellfish Allergies: Symptoms, Causes and Tricks to Manage