Maxillary Sinusitis

Maxillary sinusitis is inflammation of the maxillary sinus, the commonest sinus involved. It may be acute (up to 4 weeks), subacute or chronic (over 12 weeks).

Most acute cases follow a viral upper respiratory infection, and only about 0.5% to 2% become bacterial. Dental infection (odontogenic) causes 10% to 12% of acute maxillary sinusitis. Common organisms in bacterial disease are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis.

Pathophysiology.

Mucosal oedema blocks the maxillary ostium in the middle meatus. Retained secretions become infected, with impaired ciliary clearance, as the sinus drains against gravity.

Cheek pain or pressure, worse on bending forward, nasal blockage, purulent discharge, postnasal drip, upper tooth pain, reduced smell and fever. Symptoms may be unilateral.

Red flags.

• Orbital swelling, double vision or visual loss.
• Severe unilateral pain with facial swelling and fever.
• Numbness of the cheek, or a loose tooth with a mass.
• Severe headache or neck stiffness.

Acute bacterial sinusitis is suspected when symptoms last over 10 days without improvement, or when there is severe onset (fever over 39 C with purulent discharge and facial pain for 3 to 4 days), or a second worsening after initial improvement. Diagnosis is clinical. CT is not needed in uncomplicated disease, but is done in chronic or complicated cases. Examine the teeth, and take a swab at endoscopy in resistant disease.

Differential diagnosis.

• Viral rhinosinusitis.
• Allergic rhinitis.
• Dental abscess.
• Fungal ball.
• Maxillary sinus tumour.
• Trigeminal neuralgia.

Most acute cases settle without antibiotics in 7 to 10 days with analgesia, saline irrigation and nasal steroid. Give antibiotics when criteria for bacterial disease are met. Chronic disease is managed with saline and nasal steroid, with surgery if it persists.

• Amoxicillin: 500 mg orally three times daily for 5 to 7 days; maximum 3 g daily; monitor for rash and diarrhoea; reduce to 500 mg every 12 hours when creatinine clearance is 10 to 30 mL/min; children 40 mg/kg daily in three divided doses.
• Doxycycline (penicillin allergy): 200 mg orally on day 1, then 100 mg once daily for 5 to 7 days; maximum 200 mg daily; monitor for photosensitivity and oesophagitis; avoid in pregnancy and in children under 12 years.
• Mometasone nasal spray 50 micrograms for each spray: 2 sprays into each nostril twice daily for 2 to 4 weeks; maximum 400 micrograms daily in each nostril; monitor for epistaxis.
• Paracetamol: 1 g orally every 6 hours as needed; maximum 4 g daily (3 g daily if weight under 50 kg or chronic liver disease); monitor liver tests with prolonged use.

Monitoring. Review at 7 to 10 days; endoscopy and CT if symptoms persist beyond 12 weeks.

Referral and escalation. ENT for persistent, recurrent or complicated disease, or any red flag.

Special groups. Pregnancy: use amoxicillin, saline and paracetamol, and avoid doxycycline.