[Role of nasal sinus infections in the pathogenesis of allergic and inflammatory diseases].

Much controversy still exists about the role of viruses, bacteria and fungi in nasal sinus diseases. Viral rhinitis alone does not seem to be able to elicit clinical acute sinusitis. Bacteria determine the clinical picture and outcome of sinusitis. S. pneumoniae, H. influenzae and M. catarrhalis are the bacteria most frequently involved. Much more conflicting reports are published about normal sinus flora, the role of anaerobes and the microbiology of chronic sinusitis. The relationship between infectious and allergic diseases ise more difficult to explain. It is shown that, in particular viruses can induce the release of inflammatory mediators and modify the inflammatory process. Their role in epithelial damage, excitation of nerve fibers, sensitization of inflammatory cells, and therefore, in general hyperreactivity has also been reported. Finally, with regard to sinusitis, different hypothesis have been proposed to explain the possible links with bronchial hyperreactivity.