In my opinion, classification of the temporality of the disease has a direct relationship in two main aspects, treatment and prognosis. Whereas acute scenarios tend to have an infectious etiology, chronicity is related to a state of persistent inflamation with the subsequent mucociliary disfunction. Such characteristics are to be taken in consideration when treating a patient. Regarding the subacute period, I believe its more common in patients who are prone to chronicity and in those with a considerable atopic backround , like in allergic rhinosinusitis.

I agree with Luis in that classification of rhinosinusitis to acute & chronic can draw the line of treatment but what is the proof that subacute period of disease is more common in patients who are prone to chronicity and those with a considerable atopic background?

Rhinosinusitis should be classified in acute and chronic only, if they last less or more of 3 months respectively.

RS should be classified in to acute and chronic varieties and subclassified in to types, if the patient has anotomical defects like DNS etc.. or if patient has polyposis/PAR etc..

Which helps in planning the treatment.