Ramaswamy AT, et al. - Given that most people with eosinophilic esophagitis (EoE), an inflammatory disease of the esophagus, manifest atopic/allergic disease, researchers sought to characterize the specific allergens to which immunoglobulin E (IgE) is directed in these cases. From 25 individuals with dysphagia and suspicion of EoE, they prospectively obtained mucosal brush biopsy and solid tissue biopsy specimens. No difference in total IgE harvested between the 2 biopsy methods or between the EoE-positive (N = 12) and EoE-negative (N = 13) groups, was observed. They noted low levels of serum-specific IgE. This suggests the existence of other inflammatory mechanisms, besides type I, IgE-mediated, allergen-specific hypersensitivity, as the primary catalyst for mucosal eosinophilia. To identify more targeted diagnostic and treatment strategies for individuals who present with dysphagia and esophageal eosinophilia, they recommend clarification of the role of both IgE-mediated and non–IgE-mediated inflammatory mechanisms.