Avoid this diagnosis as much as possible, since it’s so easy to Rx antibiotics “just in case.” But consider it if:
- Normal URI had begun to resolve, then suddenly got worse (this is the main finding).
- Fever PLUS unilateral purulent nasal discharge PLUS ipsilateral facial discomfort / sinus tenderness / maxillary tooth tenderness to percussion (with a tongue blade)
- CNS signs or symptoms go straight to ER
- Unilateral purulent discharge (visible to examiner) PLUS focal facial discomfort — soft call, but useful if Sx lasting 10 days without improvement
- Have lower threshold for Dx if pt is immunocompromised
See Infectious Disease Society of America Guidelines for Dx & Tx of bacterial sinusitis.