Newest member of allergic march: eosinophilic esophagitis
A link found between allergic comorbidities and an eosinophilic esophagitis diagnosis suggests that the painful inflammation of the esophagus may be a late manifestation of the allergic march, or the natural history of the childhood development of allergic conditions.
“The allergic march is an important concept in the field of allergy that has been around for decades,” David A. Hill, MD, PhD, pediatric allergist at the Children’s Hospital of Philadelphia (CHOP), told Infectious Diseases in Children. “However, like any long-standing tenet of medicine, it was important to test and update the allergic march model to ensure it was inclusive of a newly emerging food allergy known as eosinophilic esophagitis (EoE).”
Hill and colleagues used electronic medical record data for 130,435 children within the CHOP primary care network to examine the natural histories of atopic dermatitis, IgE-mediated food allergy (IgE-FA), asthma, EoE and allergic rhinitis in individual patients. In case-controlled analyses, they studied the influence that existing allergic conditions had on the frequency of EoE diagnoses.
During the observation period, which took place from Jan. 1, 2001, to Dec. 31, 2017, 139 children developed EoE (prevalence of 0.11%). According to the study, the peak age of diagnosis for EoE occurred at 2.6 years, whereas the peak age of diagnosis for atopic dermatitis, IgE-FA, asthma and allergic rhinitis were 0.3, 1, 1.1 and 2.1 years, respectively.
A child’s risk of developing of EoE increased with the presence of other allergic diseases of childhood, such as eczema, food allergies or asthma, Hill said.
According to the study, both the independent and cumulative presence of established members of the allergic march are associated with the future development of EoE, specifically the independent presence of atopic dermatitis (HR = 3.2; 95% CI, 2.2-4.6), IgE-FA (HR = 9.1; 95% CI, 6.5-12.6) and asthma (HR = 1.9; 95% CI, 1.3-2.7). Furthermore, children with more than one (HR = 2.45; 95% CI, 1.56-3.87), two (HR = 5.6; 95% CI, 3.52-8.9), three (HR = 9.13; 95% CI, 5.22-15.96) or more allergic conditions experienced an increased risk for an EoE diagnosis. Hill and colleagues found that children with allergic rhinitis showed increased rates of subsequent EoE diagnosis (HR = 2.8; 95% CI 2-3.9). Additionally, the presence of EoE was associated with increased rates of future allergic rhinitis diagnosis (HR = 2.5; 95% CI 1.7-3.5).
“We were surprised by the strength of the associations we found,” Hill said. “For example, a child with three allergic comorbidities was approximately nine times more likely to develop EoE as compared with a healthy child.”
Hill and colleagues suggest that the inflammatory conditions meet the epidemiologic criteria and is a late-stage manifestation of the allergic march.
“The next steps are to try to understand the allergic pathways that are active in children and responsible for the allergic march. This will require both basic research studies in disease models, as well as additional studies of patients,” Hill said. “By understanding these pathways better, we are hopeful that we may be able to block in the allergic march in the future.” – by Marley Ghizzone
Disclosures: Hill reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.