Local pathogenic bacteria in allergic rhinitis: a novel concept of its pathogenesis

It is still unclear to what extent microorganisms are involved in the pathogenesis of allergic rhinitis.

Therefore, we examined the mucosal colonization with potential pathogenic bacteria (PPB) of the nasal cavity in allergic and nonallergic subjects.

In an open prospective study of 389 office workers (297 men, mean age 42.5 years, and 92 women, mean age 36.7 years), bacterial swabs were taken selectively from both nasal cavities. Standard skin tests for various aeroallergens and negative control tests were conducted in parallel in these subjects.

In the 389 subjects, we found positive skin tests in 58 (15%); 37 of these revealed a high level of sensitivity, whilst the other 21 persons had low to moderate levels. Ninety percent of the 58 sensitive persons had PPB in their nasal cavity while only 36% (119) of the remaining 331 subjects with negative skin tests were shown to have PPB in nasal cultures (p < 0.001). Sixty-four percent of the sensitized subjects with PPB were found to have more than 2 PPB species and a positive correlation with the intensity of the skin reaction. In contrast, only 18% (22) of the 119 nonallergic test persons with PPB had more than 1 PPB species.

This finding of an unusually high frequency of nasal PPB in subjects with positive skin tests to aeroallergens may indicate an involvement of PPB in the pathogenesis of allergic rhinitis. Yet, further data are still lacking to support this novel concept.