Screening asthma clinics reveals higher eosinophilic esophagitis rates in children

A team of researchers at the Medical College of Wisconsin set out to answer a straightforward question: how many children with asthma also have eosinophilic esophagitis, a chronic inflammatory condition of the food pipe that often goes undetected? What they found was striking enough to reshape how pediatric asthma clinics might approach their patients going forward.

The study, published in June in The Journal of Allergy and Clinical Immunology: In Practice, involved 189 children and young teenagers with asthma, ages 3 to 17, who visited a tertiary care center's asthma and allergy clinic. Researchers led by Robert E. Becker, M.D., asked these patients or their parents to complete a modified symptom survey designed to screen for eosinophilic esophagitis—a condition where white blood cells accumulate in the esophagus, causing inflammation and difficulty swallowing. The screening tool was noninvasive, meaning it required no procedures, just answers to questions about what the children experienced.

The results were unexpected. More than four in five patients screened positive for symptoms that could indicate eosinophilic esophagitis. Of those flagged by the screening, fewer than half were referred to a gastroenterologist for further evaluation. Of those referred, only about six in ten actually completed the referral and underwent endoscopy—the procedure where a thin camera is threaded down the throat to visualize the esophagus and take tissue samples. Among the 24 children who made it through to endoscopy, eight were diagnosed with eosinophilic esophagitis. That's one in three.

When the researchers calculated what this meant for the broader population of asthmatic children in their clinic, the prevalence jumped into focus: roughly 8 percent of all pediatric asthma patients had eosinophilic esophagitis. When accounting for children whose families didn't participate in the study or who dropped out along the way, that figure climbed to nearly 14 percent. For context, eosinophilic esophagitis was long considered a rare disease. These numbers suggested it was far more common than previously recognized, at least among children already dealing with asthma.

One detail stood out in the data: vomiting was the only individual symptom that showed a statistically significant link to an actual diagnosis of eosinophilic esophagitis. Other symptoms that patients reported—difficulty swallowing, chest pain, food getting stuck—did not reliably predict who would receive a diagnosis. This suggests that screening tools may cast a wide net, catching many false positives, but certain red flags deserve particular attention.

The implications are substantial. Eosinophilic esophagitis, left untreated, can lead to fibrostenosis—a scarring and narrowing of the esophagus that becomes progressively harder to manage and can severely limit what a child can eat. Early detection offers the chance to intervene before such complications take hold. The researchers noted that screening in asthma clinics could also help address racial disparities in diagnosis; eosinophilic esophagitis has historically been identified more often in white and affluent populations, not because it occurs more frequently there, but because those communities have better access to the specialists and procedures needed to diagnose it.

The path forward is not yet clear. The study raises the question of whether every child with asthma should be screened, and if so, how to manage the flood of referrals that would follow. But it does suggest that the two conditions—asthma and eosinophilic esophagitis—may be far more intertwined than clinicians have assumed, and that a simple conversation in an asthma clinic could unlock diagnoses that have been hiding in plain sight.