| Acute sinusitis |
Up to 4 weeks of purulent nasal drainage (anterior, posterior, or both) accompanied by nasal obstruction, facial pain-pressure-fullness, or both |
| ① Purulent nasal discharge is cloudy or colored, in contrast to the clear secretions that typically accompany viral upper respiratory infection, and may be reported by the patient or observed on physical examination. |
| ② Nasal obstruction may be reported by the patient as nasal obstruction, congestion, blockage, or stuffiness, or may be diagnosed by physical examination. |
| ③ Facial pain-pressure-fullness may involve the anterior face, periorbital region, or manifest with headache that is localized or diffuse. |
| Viral sinusitis |
Acute sinusitis that is caused by, or is presumed to be caused by, viral infection. A clinician should diagnose viral rhinosinusitis when: symptoms or signs of acute sinusitis are present less than 10 days and the symptoms are not worsening |
| Acute bacterial sinusitis |
Acute sinusitis that is caused by, or is presumed to be caused by, bacterial infection. A clinician should diagnose the acute bacterial rhinosinusitis when: |
| ① symptoms or signs of acute sinusitis fail to improve within 10 days or more beyond the onset of upper respiratory symptoms, or |
| ② symptoms or signs of acute sinusitis worsen within 10 days after an initial improvement (double worsening) |
