A recent paper published by the EAACI recognizes the EoE as an allergy not mediated by Immunoglobulin E and warns against the use of allergy tests based on it to identify potential food responsible.
A working group appointed by the European Academy of Allergy, Asthma and Immunology and composed of international experts reviewed in detail the scientific evidence against the involvement of IgE in the home or in the direction of treatment of EoE.
Eosinophilic esophagitis (EoE) is a particular form of food allergy that is frequently associated with concomitant atopic diseases and immunoglobulin E (IgE) sensitization. Infiltration by eosinophils and symptoms usually respond to food elimination, although the dietary strategy used determines quite different results. Thus, exclusive feeding with an elemental diet has been recognized as the most effective dietary intervention in patients of all ages in terms of inducing disease remission, but its several disadvantages limit their use in clinical practice. The attempts of identifying food triggers by the clinical histories of the affected patients were unsuccessful, because patients do not generally associate the onset of symptoms with consumption of specific foods. Skin allergy testing was thought to be capable of identifying the specific food(s) to be avoided while providing patients with convenience, feasibility, and improved quality of life, as they would only have to eliminate certain foods to achieve results similar to those obtained with elemental diets. Unfortunately, these goals could not be achieved, as demonstrated by the limited remission rate achieved with this strategy of only 45.5% according to a recent meta-analysis, with broad heterogeneity in the results, indicating low reproducibility. Moreover, these results were significantly lower for adults than for children (32.2% vs 47.9%).
Compared with controls, patients with EoE are usually sensitized to several different foods and aeroallergens, as demonstrated not only by skin allergy test results, but also by higher values of serum food-specific IgE. After repeated studies documenting the very limited utility of serum food-specific IgE in the management of EoE patients, the strategy of measuring specific IgE against single allergen molecules by means of microarray assay–based component-resolved diagnosis (CRD) was also recently assessed for its potential to guide specific dietary management of EoE. However, a prospective study failed to demonstrate the efficacy of CRDbased dietary treatment in EoE patients.
In parallel with the repeatedly documented limitations of IgE-based allergy testing for controlling EoE, there is a growing body of evidence against the involvement of IgE-mediated reactions in the pathogenesis of the disease. Moreover, EoE is increasingly recognized as a disease that is basically restricted to the esophagus, with very limited systemic expression. Thus, serum IgE levels do not necessarily correlate with the clinical or histopathological activity of the disease and have repeatedly shown very limited sensitivity and specificity (around 50%, the same of throwing a coin and make a cross) for identifying the foods responsible for EoE. Exposure to such trigger foods rarely causes anaphylaxis. Blocking IgE with monoclonal antibodies (omalizumab) has repeatedly been found to be ineffective in improving EoE in children and adults, according to observational studies and a recent RCT.
All these reasons strongly support the evidence that EoE is generally non-IgE-mediated, and advise against carrying out IgE-based skin and/or serum tests as a attempt to identify specific food triggers. The identification of offending foods by empirical elimination diets and controlled reintroduction of foods is, at present, the only reliable method for identifying specific food triggers.
Read more at http://www.ncbi.nlm.nih.gov/pubmed/26799684