In 2017, roughly 5% of newborns had a peanut allergy. That’s a stark increase from the roughly 1% that characterized previous decades, according to researchers.
Jay Lieberman, MD
Approximately 1.25 million, or 2.2% of all children and adolescents in the United States have peanut allergy, according to new research released at the annual meeting of the American College of Asthma, Allergy and Immunology in Seattle, Washington.
That’s a steep increase from the roughly 1% total that characterized the decades leading up to the 2010s, according to lead investigator Jay Lieberman, MD, of Le Bonheur Children’s Hospital in Memphis, Tennessee.
“Peanut allergy, like other food allergies has increased over the past couple of decades,” Lieberman said in an interview with MD Magazine. “If you do the numbers right, in just about any public school, each grade is going to have a student with a peanut allergy. That’s based on various techniques, including surveys as well as coding.”
In the study, the annual incidence of peanut allergy in newborns also increased since data from the US Census Bureau became available in 2001. That year, ­66,000, or 1.7% of all babies were born with a peanut allergy. By 2017, those numbers had climbed to 210,000 and 5.2%, respectively. Common comorbidities among patients with peanut allergy included eczema (63%) and asthma (61%). Moreover, 35% of patients with peanut allergy had 1 or more additional food allergy.
In terms of diagnosis, of the estimated 2.2% of children and adolescents with peanut allergy, investigators found that about 500,000 were diagnosed by allergists, 370,000 were diagnosed by pediatricians and managed by allergists, and 380,000 were diagnosed and managed by outside allergists.
“Frequently you’ll find that the emergency department is making a diagnosis the first time a patient has a peanut allergy reaction. The patient goes to the ED first, so we want our pediatric physicians to be a little better at recognizing it and referring on when appropriate. A lot of these patients are getting to the allergist before they get to that first diagnosis. We’re hopeful that they’ll get diagnosed before they get an allergist,” Lieberman said.
To arrive at their estimates, Lieberman and colleagues examined longitudinal data between January 2011 and December 2017 from a geographically and payer-type representative real-world US healthcare claims database. Patients aged 4-17 years with peanut allergy were identified using diagnostic codes and/or services indicated peanut allergy-associated severe reactions/anaphylaxis.
Prevalence estimates were projected, accounting for dataset capture rates by healthcare setting (40% outpatient clinic, 25% hospital), 30% under-coding, and patient under-presenting (8-15% based on patient age). Estimated annual incidence was defined as peanut allergy births as a proportion of all 1-year-old-babies. Then, incidence was computed from prevalence estimates, aging patients back to age 1, adjusting for spontaneous outgrowth of peanut allergy (27% by age 12.)
Both the number of total births with peanut allergy and the percentage of all newborns has increased every single year since 2001, with the exception being the period between 2001-2002, when the number and percentage dropped from 66,000 and 1.7% to 65,000 and 1.6%.
The steady increase in both incidence and prevalence of peanut allergy suggests that the impact of peanut allergy may be greater than previously reported, according to Lieberman.
“Given how prevalent peanut allergy is, we should be trying to do prevention strategies as often as we can. For peanut allergy, that’s early introduction in high risk populations — it can really decrease the prevalence,” he said.