Understanding the Burden of Multi-Food Allergy and Allergic Comorbidities in U.S. Children

Funded by Food Allergy Fund

Dr. Christopher M. Warren as Principal Investigator

Food allergy is a growing public health concern in the US and globally. However, converging epidemiologic data suggest that it is relatively rare for it to occur alone. For example, national survey data published in 2023 suggest that nearly half of US food allergy patients are allergic to multiple foods. It is also clear that atopic dermatitis and food allergy are strongly correlated, with up to half of children with early-onset, severe atopic dermatitis going on to develop at least one food allergy during infancy. Many experts describe an “allergic march” of comorbid chronic conditions that often begins with atopic dermatitis, and then goes on to include food allergy, asthma, and environmental allergies. However, since in their current form state and federal chronic disease surveillance systems do not adequately capture the US population-level burden of food allergy, understanding remains limited regarding the full impact that food allergies and associated allergic conditions impose on patients, families, health systems and society more broadly.

Our team at Northwestern University and Lurie Children’s Hospital of Chicago has led a multi-site, collaborative effort to recruit and follow a large cohort of English- and Spanish-speaking children with food allergy for the past 7 years—carefully assessing their food allergy status via clinical visits, quarterly surveys, blood, skin and stool microbiome collection, as well as regular extraction of electronic health record data. Together these data allow us to paint a much more complete picture of the allergic disease burden experienced by pediatric food allergy patients in the US, who appear to be at elevated risk of many related conditions, including (but not limited) to atopic dermatitis, asthma, environmental allergies, eosinophilic esophagitis, oral allergy syndrome, and chronic urticaria.

The Food Allergy Fund is supporting systematic efforts to better characterize the degree to which these chronic allergic conditions co-occur, as well as understand modifiable determinants of allergic disease burden that can be targeted by scalable interventions. One advantage of the assembled NIAID-supported longitudinal cohort is its very large (N>1500) sample of parents and children who span the entire pediatric age spectrum, from infancy to young adulthood. This allows examination of not only the early life factors that are increasingly acknowledged to play key roles in the development of multiple allergic conditions but also factors that are present throughout childhood that may also be disease modifying. Preliminary findings from these FAF-supported analyses presented at the 2025 Food Allergy Fund Summit identify remarkably high rates of multi-food allergy and allergic comorbidities in this large, geographically, racially/ethnically and socioeconomically diverse cohort of children with allergist-confirmed FA. Furthermore, these analyses highlight a potentially causal role of greater eczema severity and duration, not only in infancy, but into mid- and later childhood. Specifically, children with more severe and persistent eczema appear to be at substantially greater risk of multi-food allergy, as well as development of additional allergic diseases as they age. Ongoing work seeks to further clarify these associations, as well as further understand the growing burden and etiology of multi-food allergy and related chronic conditions in the US population.