IGHE and allergic disease: TheLacrytest has very high specificity and positive predictive value (100%); thus,a positive test could point to an allergic aetiology, but the low number of positivecases found in the group of IgE-mediated allergy (sensitivity 20%, negativepredictive value 38.46%) indicates that this test cannot be the only parameter toachieve an aetiological diagnosis, as occurs with serum IgE.