Researchers analyzed existing studies to see if allergy treatments might be linked to a rare swallowing condition called eosinophilic esophagitis (EoE). They looked at 17 studies involving patients receiving allergen immunotherapy—15 studies on food desensitization (3,302 patients) and 2 studies on sublingual immunotherapy for airborne allergens like pollen (1,436 patients).
The analysis found that in food desensitization studies, about 2.3% of patients developed confirmed EoE. In the studies on sublingual immunotherapy for airborne allergens, no cases of EoE were reported among the 1,436 patients. EoE was described as a potential side effect in these studies.
It's important to understand this was a review of observational studies, which can show associations but not prove that the treatment directly causes the condition. The finding about airborne allergen treatments is based on only two studies, so more research is needed. Patients considering or receiving allergy treatments should discuss any concerns about potential side effects with their doctor.