Table 1.

Classification of types of rhinosinusitis [5]

Temporal designation	Description and duration of symptoms
Acute	Symptoms <4 wks' duration, including persistent upper respiratory tract infection, purulent rhinorrhea, postnasal drainage, anosmia, nasal congestion, facial pain, headache, fever, cough, and purulent discharge
Subacute	Unresolved acute symptoms of sinus inflammation lasting 4–8 wk
Chronic	Same symptoms as with acute rhinosinusitis but ≥8 wks' duration; degree of symptom severity varies
Recurrent	≥3 episodes of acute rhinosinusitis annually; patients may be infected by different organisms at varying times