There’s a new food allergy in town, and it seems that children with existing allergies at an increased risk of developing it. From the Children’s Hospital of Philadelphia (CHOP), scientists describe eosinophilic esophagitis (EoE), an inflammatory condition affecting the esophagus.
EoE is characterized by an abnormal influx of white blood cells, called eosinophils, into the esophagus. Eosinophils cause inflammation, which can lead to painful swallowing, stomach aches, and food impaction (food getting stuck in the esophagus). Unlike other food allergies, those affected by EoE are unlikely to die from the condition, but EoE affects a large amount of people in the general population.
Similar to other food allergies, EoE-related inflammation is triggered by consuming specific foods. However, it may take several tests and a considerable amount of time for clinicians to figure out which foods can cause EoE. Many people with EoE are either misdiagnosed or not diagnosed at all. Whether it’s a skin, food, or respiratory allergy, those with existing allergies are at an increased risk of EoE, CHOP scientists show in their new study.
This study is the first to dub EoE as a stop along the “allergic march,” the phenomenon referred to by allergy experts that describes the natural sequence of allergic events that occur in the first five years of life. Also called the “Atopic March,” this sequence of events is characterized by various immunoglobulin E (IgE) antibody responses and clinical symptoms, according to the World Allergy Organization. For example first a child could develop atopic dermatitis (eczema), then an anaphylactic food allergy, and then a respiratory allergy, like asthma.
"The more allergies a child has, the higher is that child's risk of developing EoE," explained David A. Hill, MD, PhD, who led the study. "The connection among these allergies suggests a common underlying biological cause, and also may imply that if we can successfully treat an earlier type of allergy, we may prevent later allergies."
Hill and his team analyzed various data from more than 130,000 study participants who were followed from birth to adolescence. Researchers looked at which participants developed allergic diseases, comparing the risk of developing EoE between allergic and non-allergic children.
"We found that if children had three allergies other than EoE, they were nine times more likely to develop EoE than children with no pre-existing allergies," Hill explained. The “peak age” of an EoE diagnosis was 2.6 years old. Hill also found that children with EoE were more likely to develop allergic rhinitis (seasonal allergies).
Going forward, Hill and others want to know more about the biological mechanisms connecting different allergic diseases. But for now, Hill just wants to make sure that children with multiple allergies are screened early on for EoE: "Ultimately, we hope to find that intervening earlier in the allergic march, for example, in treating allergic skin conditions, may interrupt the march and prevent the child from developing later disorders such as EoE."
The present study was published in the Journal of Allergy and Clinical Immunology: In Practice.