Epidemiology of chronic rhinosinusitis.

PROBLEM OF DEFINITION The discrepancy of definitions results mainly from the use of diVerent criteria such as symptom duration or intensity, the type of selected symptoms, and also from the need for and lack of other exploration methods such as imaging or bacteriological culture. In the definition proposed by the International Conference on Sinus Disease in 1993 the criteria for chronic sinusitis in adults were persistent symptoms and signs for eight weeks or four episodes per year of recurrent acute sinusitis, each lasting at least 10 days, in association with persistent changes on the computed tomographic (CT) scan four weeks after medical treatment without intervening acute infection. The International Consensus Meeting on the Management of Rhinosinusitis in Children held in Brussels in 1996 proposed that two aspects should be taken into account when defining chronic rhinosinusitis: the pathology (infection of the sinus) and the clinical symptoms (low grade symptoms and signs persisting for longer than 12 weeks). We will not discuss nasal polyposis here.