Allergic and nonallergic rhinitis: their characterization with attention to the meaning of nasal eosinophilia.

We examined the differences between allergic and nonallergic rhinitis. One hundred forty-two patients were evaluated. Forty-eight patients were diagnosed as having allergic rhinitis (AR) on the basis of histories correlating with skin tests and markedly elevated total serum IgE levels. Forty-two percent of these patients had nasal eosinophilia (greater than or equal to 25%) and 58% had histories or findings consistent with asthma. Fifty-two individuals had no evidence for immunologic nasal disease, incriminated physical agents as precipitants, and demonstrated no associated respiratory pathology. These patients were classified as having vasomotor rhinitis (VMR). Twenty-one patients had symptoms similar to those of patients with VMR but they demonstrated nasal eosinophilia and were classified as having eosinophilic nonallergic rhinitis (ENR). These patients had a high prevalence of nasal polyps and were significantly more responsive to medical therapy than any group studied. It is concluded that nasal eosinophilia is of little value in the evaluation of AR but provides significant information regarding the therapy and prognosis in nonallergic rhinitis.