Sinusitis (sinus infection)

Sinusitis is inflammation of the tissue lining the sinuses — air-filled cavities in the face and skull. When sinuses become blocked and filled with fluid, viruses, bacteria, or fungi can grow and cause infection. Most acute sinusitis follows a viral upper respiratory infection and improves on its own; only a minority are primarily bacterial and benefit from antibiotics.

Chronic sinusitis lasts 12 weeks or longer despite treatment attempts and may involve ongoing inflammation rather than simple infection. Treatment depends on whether the problem is acute or chronic and on the likely cause. Supportive care, saline irrigation, intranasal corticosteroids, and judicious use of antibiotics or surgery when indicated form the main approaches.

Common symptoms include:

• Facial pain or pressure (forehead, cheeks, or around the eyes), often worse when bending forward
• Nasal congestion and obstruction
• Thick nasal discharge (yellow or green) or postnasal drip
• Reduced sense of smell
• Cough, often worse at night
• Ear pressure, fatigue, and dental pain in the upper teeth
• Halitosis
• Fever (more common in acute bacterial infection)

Acute sinusitis lasts less than 4 weeks; chronic sinusitis persists 12 weeks or more, often with less fever but ongoing congestion and facial discomfort.

Most acute sinusitis is caused by viruses (the same viruses that cause colds). Bacterial sinusitis may develop as a secondary infection. Chronic sinusitis involves persistent inflammation and may be associated with:

• Nasal polyps or deviated septum blocking drainage
• Allergies and allergic rhinitis
• Asthma and aspirin-exacerbated respiratory disease
• Immune deficiency or immotile cilia disorders
• Fungal colonization or allergic fungal rhinosinusitis in selected patients
• Environmental irritants and smoking

Risk factors include allergic rhinitis, nasal polyps, structural blockage, frequent upper respiratory infections, asthma, immune disorders, dental infections (for some maxillary sinusitis), smoking, and exposure to pollutants. Children in daycare and people with cystic fibrosis or primary ciliary dyskinesia have higher rates of chronic disease.

Complications are uncommon but can be serious:

• Orbital cellulitis or abscess
• Meningitis or brain abscess (rare)
• Osteomyelitis of facial bones
• Chronic symptoms that impair sleep, productivity, and quality of life
• Worsening of asthma control

Helpful measures:

• Practice hand hygiene and avoid close contact with people who have colds
• Manage allergies effectively
• Avoid cigarette smoke and other irritants
• Use a humidifier in dry environments
• Consider saline nasal irrigation as a preventive habit if you have frequent sinus problems
• Stay up to date with recommended vaccines (influenza, COVID-19)

Acute sinusitis is usually diagnosed clinically. Imaging is not needed for uncomplicated acute cases. For chronic or recurrent disease, or when complications are suspected:

• Nasal endoscopy
• CT scan of the sinuses (preferred imaging for chronic sinusitis and preoperative planning)
• Allergy testing when allergic drivers are suspected
• Cultures in selected refractory or immunocompromised patients (ideally endoscopically guided)

Differentiating viral from bacterial acute sinusitis relies on duration, pattern (worsening after improvement), and severity rather than mucus color alone.

See a clinician if symptoms last more than 10 days without improvement, worsen after initial improvement (double sickening), or are accompanied by high fever, severe facial pain, or swelling. Seek urgent care for vision changes, severe headache, neck stiffness, confusion, or swelling around the eyes — possible signs of spread beyond the sinuses.

Acute sinusitis

• Supportive care: hydration, analgesics, saline irrigation, intranasal corticosteroids
• Intranasal decongestants only for a few days to avoid rebound congestion
• Antibiotics (e.g., amoxicillin or amoxicillin-clavulanate when indicated) for likely bacterial disease — typically symptoms ≥10 days, severe onset, or double sickening
• Avoid unnecessary antibiotics for viral illness

Chronic sinusitis

• Daily saline irrigation and long-term intranasal corticosteroids
• Short courses of oral corticosteroids for severe flares or extensive polyps in selected patients
• Culture-directed antibiotics for acute exacerbations when bacterial infection is likely
• Biologics (e.g., dupilumab and others) for chronic rhinosinusitis with nasal polyps in eligible patients
• Functional endoscopic sinus surgery when medical therapy fails, to improve drainage and access for topical therapies

Supportive measures that help many people:

• Saline nasal irrigation (neti pot, squeeze bottle) with distilled, sterile, or previously boiled and cooled water
• Intranasal steroid sprays used consistently and with correct technique
• Warm facial compresses for comfort
• Adequate hydration and rest
• Elevation of the head during sleep
• Avoidance of smoke and known irritants
• Over-the-counter pain relievers as needed

Bring:

• Symptom duration, pattern, and severity
• History of allergies, asthma, polyps, or prior sinus surgery
• List of medicines and previous antibiotics for sinus infections
• Questions about whether antibiotics are needed, imaging, or referral to an ENT specialist