Antritis (Maxillary Sinusitis): Causes, Symptoms, and Treatment

Antritis is inflammation of the maxillary sinus (antrum of Highmore). Usually part of rhinosinusitis.

Causes

• Viral URI (common cold): Most common; edema blocks ostium → stasis → secondary bacterial infection.
• Bacterial: S. pneumoniae, H. influenzae, M. catarrhalis (acute); anaerobes, Staph (chronic).
• Allergic rhinitis: Chronic inflammation, polyp formation, ostial obstruction.
• Anatomic variants: Deviated septum, concha bullosa, Haller cells, narrow osteomeatal complex.
• Dental origin (odontogenic): Periapical infection of maxillary molars/premolars → sinus floor perforation (10–40% of chronic cases).
• Environmental irritants: Smoke, pollutants, occupational exposures.

Symptoms

Facial pain/pressure (cheek, infraorbital), purulent nasal discharge, nasal obstruction, hyposmia, postnasal drip, cough, dental pain (referred), fever (acute bacterial).

Treatment

• Acute viral: Supportive (saline irrigation, analgesics, decongestants short-term).
• Acute bacterial (≥10 days, worsening, severe): Amoxicillin-clavulanate 5–7 days; alternatives if allergic.
• Chronic (≥12 weeks): Culture-directed antibiotics, intranasal corticosteroids, saline irrigation, address anatomy/allergy. FESS (functional endoscopic sinus surgery) if refractory.
• Odontogenic: Dental treatment (RCT/extraction) + sinus therapy.