At least 15 percent of people with food allergies develop the condition after the age of 18, a new study suggests.
Our understanding of the prevalence and characteristics of food allergy have been based mostly on studies examining the condition in children. In contrast, this study, published in JACI: In Practice in August 2014, revealed new information about many aspects of adult-onset food allergy, including age of onset and most common allergic triggers.
Researchers from Chicago’s Northwestern University Feinberg School of Medicine reviewed medical records from a database of 1,111 patients who had been diagnosed with food allergy by physicians at Northwestern’s adult allergy clinics. They determined that 171 patients met criteria that included age at the time of diagnosis, medical history, test results, and international diagnosis codes. Based on an assessment of these patients, the researchers found that:
- The age of first reaction peaked during the early 30s, with patients’ ages ranging from 18-86 years.
- An older age at the time of diagnosis was associated with higher risk for severe reactions.
- A higher percentage of the patients were female, which contrasts with the male dominance of food allergy in children.
- The five most common food allergies among this group were shellfish, tree nuts, fish, soy and peanut. Study participants also identified 14 other foods as allergic triggers.
- Approximately 16% of patients were allergic to more than one food.
Although the researchers state that additional studies are needed to provide “a more complete picture of this patient group,” they note that these findings support the importance of understanding food allergy in adults, “particularly in understanding that new-onset food allergy is evident across a broad age range during adulthood.”