BACKGROUND It has been proposed that some patients with nonallergic rhinitis may have "localized allergy" of the nasal mucosa. Nasal challenges with aeroallergens can help determine whether a patient is clinically allergic via an IgE-mediated pathway. OBJECTIVE To determine the prevalence of localized allergy in patients with negative skin prick test results via nasal challenges with an array of allergens. METHODS Twenty individuals with perennial rhinitis and negative epicutaneous test results to common perennial aeroallergens underwent nasal challenges to glycerin, Alternaria, cockroach, timothy grass, cat hair, and Dermatophagoides pteronyssinus. Total symptom scores, peak nasal inspiratory flow rates, and nasal eosinophil counts were determined. RESULTS Of 20 patients with nonallergic rhinitis, 4 were hyperresponsive to glycerin and were not subsequently challenged. Eleven patients had negative nasal challenges. Five patients developed positive challenges (total symptom score > or = 5) to 7 allergens. These 5 patients returned for nasal provocation testing to their offending allergens, and these repeated challenges were negative. Three control subjects with allergic rhinitis developed positive challenges after nasal allergen challenge. CONCLUSIONS Although some individuals with nonallergic rhinitis can have positive nasal allergen challenges, these results were not reproducible in the present patient population.