Acute Bacterial Sinusitis

Key facts

• Acute bacterial sinusitis is a short-term bacterial infection of the sinus cavities, usually developing after a cold that does not improve as expected.
• It causes facial pain or pressure, thick yellow or green nasal discharge, a reduced sense of smell, and sometimes fever. Symptoms that persist beyond ten days or worsen after initial improvement point to a bacterial cause rather than a lingering cold.
• Treatment is a course of antibiotics, most often cefuroxime, a cephalosporin that covers the bacteria typically responsible.
• See a doctor promptly if you develop severe facial swelling, vision changes, a stiff neck, or a high fever, since these can signal the infection has spread beyond the sinuses.

Telling it apart from a cold

A common cold usually peaks around day three and clears within seven to ten days. Bacterial sinusitis is more likely when symptoms persist beyond ten days without improving, or when they worsen again after an initial recovery. Classic features include thick discoloured nasal discharge, facial pressure that's often worse when you bend forward, a blunted sense of smell, and a dull headache centred around the forehead or cheeks. Fever appears in some cases but not all.

How it's treated

When a bacterial cause is confirmed or strongly suspected, a course of antibiotics is the standard approach. Cefuroxime, a second-generation cephalosporin, is commonly used for this infection because it covers the bacteria most often responsible, including Streptococcus pneumoniae and Haemophilus influenzae. Complete the full course even if symptoms ease early, so the infection clears fully.

Saline nasal rinses and adequate hydration help clear mucus and relieve pressure alongside any antibiotic.

When to see a doctor

Seek medical attention promptly if you develop severe facial swelling, changes in vision, a stiff neck, or a high fever, as these may signal the infection spreading beyond the sinuses.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.