Acute sinusitis presents with pain originating in the maxillary, frontal, ethmoid, or sphenoid sinuses, with the maxillary sinus being by far the commonest. Onset of facial pain is often preceded by non-specific symptoms of upper respiratory inflammation and there may be systemic signs of inflammation. The bacterial causes of acute sinusitis are the same as acute otitis media. If X-ray or culture confirms the clinical diagnosis then antibiotics can substantially reduce the duration of symptoms. However, neither of these investigations is routinely available in primary care.