1.2 Million Children and Teens Have Peanut Allergies

SEATTLE -- Roughly 1.2 million children and teens in the United States -- or just over 2% of the non-adult population -- have peanut allergies, newly reported studies show.

Two separate studies -- one based on survey data, and the other a longitudinal analysis of a large healthcare claims database -- estimate the current incidence of peanut allergies to be 2.2% among U.S. children and adolescents.

Among babies under the age of 1 year, one of the studies showed a roughly three-fold increase in peanut allergy between 2001 and 2017, with the most current incidence estimated to be 5.2%.

Both studies were reported here at the American College of Allergy, Asthma, and Immunology's Annual Scientific Meeting.

The prevalence of food allergies, including peanut allergy, has increased relatively steadily in the United States over the last few decades, but there is reason to believe that the peanut allergy burden among children and adolescents is beginning to plateau, Jay Lieberman, MD, of LeBonheur Children's Hospital in Memphis, told MedPage Today.

He said that the new National Institute of Allergy and Infectious Diseases-sponsored guidelines recommending the early introduction of peanut (between 4 to 6 months of age) in high-risk children are expected to reduce the number of childhood peanut allergies in coming years.

"We can't say that with certainty yet, but that is the hope if the guidelines are followed," he said.

In the study he presented, he and his colleagues identified children and adolescents ages 4-17 with peanut allergies, using diagnostic codes and/or services indicating peanut allergy-associated severe reactions, such as 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, and peanut allergy incidence was computed from prevalence estimates, aging patients back to age 1 and adjusting for spontaneous outgrowth of peanut allergy (27% by age 12).

Among the main findings were the following:

• Estimated peanut allergy prevalence was 1.25 million (2.2%) in 2017
• Among the children and adolescents diagnosed with peanut allergies, about 500,000 were diagnosed by allergists; 370,000 by pediatricians and managed by allergists; and 380,000 were diagnosed and managed by practitioners other than allergists
• Common comorbidities included eczema (63%) and asthma (61%), and one or more additional food allergies (35%)
• The annual peanut allergy incidence in 1-year-olds increased between 2001 and 2017, from an estimated 1.7% to 5.2%

The researchers concluded that the increasing prevalence in peanut allergies among children and teens suggests that the impact of peanut allergy may be greater than previously reported.

In the other study, Ruchi Gupta, MD, of Northwestern Feinberg School of Medicine in Chicago, and colleagues, used a nationally representative survey of close to 52,000 U.S. households conducted between 2015 and 2016, and also concluded that approximately 2.2% of children and adolescents in the United States have peanut allergies. That data showed the following, that among children with peanut allergies:

• 59.2% (95% CI, 53.6-64.6) had experienced a severe reaction

• 54.8% (95% CI, 49.1-60.3) had multiple food allergies

• 73.0% (95% CI, 68.0-77.5) had a current epinephrine prescription

• 50.4% (95% CI, 44.9-55.0) had at least one lifetime emergency department (ED) visit, with 22.9% (95% CI, 19.1-27.2) having had an ED visit during the past year

Still needed, Gupta and co-authors said, is additional study to better understand potential predictors of adult-onset food allergy.