Last edited 09/2018

Rhinosinusitis is generally classified according to the duration into:

  • acute rhinosinusitis (ARS) - if duration of symptoms is less than 12 weeks
  • chronic rhinosinusitis (CRS)  - if lasting more than 12 weeks (with or without acute exacerbations) (1)

Acute rhinosinusitis can be further divided into

  • acute viral rhinosinusitis (common cold) - duration of symptoms of less than 10 days
  • acute post-viral rhinosinusitis - defined by an increase in symptoms after 5 days or persistent symptoms after 10 days with less than 12 weeks duration.
  • acute bacterial rhinosinusitis—defined by the presence of at least three symptoms or signs of
    • discoloured discharge (with unilateral predominance) and purulent secretions
    • severe local pain (with unilateral predominance)
    • fever (>38°C)
    • elevated erythrocyte sedimentation rate or C reactive protein
    • ‘double sickening’ (i.e. a deterioration after an initial milder phase of illness) (1)
  • in recurrent acute sinusitis
    • there are four or more episodes of acute bacterial rhinosinusitis per year without signs or symptoms of sinusitis between episodes
    • each episode should meet the diagnostic criteria for acute bacterial sinusitis


  1. Fokkens WJ et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2012. Rhinol Suppl. 2012;23:3 p