The PROSINUS study has been designed in response to the shortage of epidemiological data in Spain on the diagnosis and treatment of acute rhinosinusitis (ARS). The name PROSINUS refers to a prospective epidemiological study whose purpose is to analyse the diagnosis and treatment of this disease in ENT offices in Spain and also to assess its socioeconomic impact.

However, 550 were subsequently excluded because they had chronic rhinosinusitis and a further 77 had a probable diagnosis of chronic rhinosinusitis. Of the 1,233 patients with a confirmed diagnosis of ARS, 1,172 have completed visit 1 of the study and 788 have also reached visit 2. Most of the patients (approx. 90%) initially had a moderate or severe disease, according to the VAS.

The definition of acute rhinosinusitis given in the 2005 EP3OS guidelines has been used for the study. At present, the diagnosis of rhinosinusitis is basically clinical; the main symptoms are nasal obstruction/congestion, impaired sense of smell, anterior or posterior rhinorrhoea, and facial pain/pressure; at least two symptoms are required to determine the presence of rhinosinusitis.

However, a further condition has been added in that the symptoms must be associated with suggestive endoscopic findings (polyps, rhinorrhoea and oedema) or changes in the sinonasal mucosa that can be identified by computerised tomography (CT).

In the review of the EP3OS position paper performed this year (Fokkens et al., 2007), it was proposed to reclassify the severity of rhinosinusitis by quantifying it on a visual analogue scale graded from 0 to 10. Under this new classification, a patient is considered to have mild disease when the score on the visual analogue scale does not exceed 4 and moderate/severe disease when at least one symptom attains a score between 4 and 10. As regards the duration of the rhinosinusitis, it is defined as acute or intermittent when disease duration is less than 12 weeks and chronic or persistent if it continues beyond 12 weeks. Acute rhinosinusitis is further subdivided into two clinical conditions: acute viral rhinosinusitis or common coldand acute/intermittent non-viral rhinosinusitis.

In viral rhinosinusitis, symptom duration is less than 10 days, while acute/intermittent non-viral rhinosinusitis is defined as an increase in symptom severity after 5 days or persistence of symptoms beyond 10 days after symptoms began. In both cases, symptom remission is complete within 12 weeks.