Intradermal Testing Doubles Identification of Allergy among 110 Immunotherapy-Responsive Patients with Eustachian Tube Dysfunction.

The purpose of this study was to determine whether the sensitivity advantage of intradermal dilutional testing (IDT) is clinically relevant in patients with obstructive Eustachian tube dysfunction (ETD) or otitis media with effusion (OME). This retrospective, private-practice cohort study compared the sensitivity of skin prick tests (SPT) vs. IDT in 110 adults and children with suspected allergy and OME. Primary outcome measure was symptom resolution from allergy immunotherapy (AIT). IDT identified 57% more patients as being allergic, and 8.6 times more reactive allergens than would have been diagnosed using only SPT. Patients diagnosed by IDT had the same degree of symptom improvement from immunotherapy, independent of allergen sensitivity (66% by SPT vs. 63% by IDT; p = 0.69, not different). Low-sensitivity allergy tests, which may fail to identify allergy in over two thirds of children aged 3 to 15 as being atopic, or among 60% of patients with ETD, may explain why many physicians do not consider allergy as a treatable etiology for their patient's OME/ETD. IDT offers superior sensitivity over SPT for detecting allergens clinically relevant to treating OME/ETD. These data strongly support increased utilization of intradermal testing and invite additional clinical outcome studies.