Reflections on current food allergy controversies: Specific IgE test application, patch testing, eosinophilic esophagitis, and probiotics

This presentation addresses four selected issues that are current controversies in the area of food allergy. First, the diagnostic proficiency of specific IgE (sIgE) measurement. sIgE testing has been a useful screening test; the higher the level, the more likely to be clinically relevant. However, published predictive values varied from one study to another. Levels derived from data on certain groups of patients reflect probabilities that can not be applied with certainty to individual patients. Several factors need to be considered in interpreting the value of sIgE in any particular patient. Definitive decisions require well-designed challenge testing. Second, a few studies suggested the usefulness of including patch testing in food allergy evaluation. It may reveal positive results that may or may not be clinically relevant. At present, its use is not generally accepted because of inconsistency in the reported findings and the lack of standardization of test materials and interpretation. It may possibly have a role in evaluating eosinophilic esophagitis (EE) more than in atopic dermatitis. Third, EE does not seem to be a new disease or is causing a miniepidemic. Its increasing diagnosis is probably because of a greater awareness and better biopsy assessment. Fourth, the usefulness of probiotics on allergy prevention or treatment has been reported by some studies but not by others. Appropriately designed studies are needed to identify the efficacious type(s) of probiotics, effective doses, method of administration, optimal time to begin, and duration of therapy.