When allergic rhinitis is not only allergic

In clinical practice it can be observed that some patients with seasonal allergic rhinitis (AR) continue to have symptoms even when the exposure to allergens is expected to be low or absent. We studied the clinical and cytological characteristics of these atypical forms of (AR) in a large population of patients.

Consecutive patients with symptoms of rhinitis and with positive skin test to pollens only were interviewed for the duration of symptoms, correlation with sensitization pattern, and presence of reactivity to nonspecific stimuli. All underwent rhinoscopy and nasal scraping for cytology.

Five hundred nineteen patients with AR were studied. Of these 519 patients 60 (11.5%) had an atypical or mixed form of rhinitis, with symptoms independent of the exposure and also elicited by nonspecific stimuli. These patients clearly differed from typical forms, especially for the nasal inflammation. They had a greater number of eosinophils and mast cells out of season (p < 0.05). Moreover, these atypical forms had, more frequently, asthma and eosinophilic polyps.

In approximately 12% of patients with AR, other mechanisms of inflammation seem to intervene. Nasal cytology can be helpful in discriminating these atypical forms.