Nonspecific IgE potential in nasal discharge for diagnosing allergic rhinitis

Given that the nasal discharge of subjects with allergic rhinitis contains IgE, we studied nonspecific IgE potential in nasal discharge as a diagnostic marker for allergic rhinitis. We divided 38 adults into 2 groups, one with 22 with Japanese cedar pollinosis and one with 16 with watery rhinorrhea negative to MAST33. The pollinosis group was exposed to Japanese cedar pollen in an environmental exposure unit, and eosinophils in nasal discharge, serum total IgE, pollen-specific IgE, and local IgE in nasal discharge were examined for the 2 groups to determine IgE levels in nasal discharge using the Allerwatch rapid test. In the pollinosis group, nasal discharge IgE correlated significantly with the number of eosinophils. The nasal discharge IgE had higher specificity than the eosinophil examination, whereas nasal discharge eosinophils had higher sensitivity than the IgE examination. We thus found that measuring IgE and eosinophils in nasal discharge is useful for clinically diagnosing allergic rhinitis.