Sinusitis (Sinus Infection)

What the sinuses are

There are 4 pairs of sinuses: maxillary (cheeks), frontal (forehead), ethmoid (between the eyes) and sphenoid (deep behind the nose). They are lined with mucus-producing tissue and drain into the nose through narrow openings. When the lining swells, from a virus, allergy or irritants, these openings block, mucus builds up and pressure develops. Trapped mucus can sometimes become infected with bacteria.

Types of sinusitis

Symptoms

• facial pain, pressure or fullness, often worse when bending forward
• blocked or stuffy nose
• thick yellow or green discharge from the nose or down the back of the throat
• reduced sense of smell and taste
• headache
• cough, often worse at night
• tooth or upper jaw pain
• fatigue and bad breath
• fever in some acute cases

Chronic sinusitis usually causes less pain and more ongoing blockage, discharge and loss of smell.

Viral vs bacterial sinusitis

Discolored mucus does not by itself mean a bacterial infection. Bacterial sinusitis is likely when:

• symptoms last 10 days or more without improving
• the illness starts severe, with fever of 39 °C (102.2 °F) or higher and thick discharge or facial pain for 3 to 4 days
• symptoms improve, then worsen again (double worsening)

Causes and risk factors

• colds and other viral infections
• allergic rhinitis
• nasal polyps
• a deviated septum or other structural narrowing
• dental infections of the upper teeth
• smoking and secondhand smoke
• asthma and aspirin-exacerbated respiratory disease
• cystic fibrosis and immune deficiencies

Diagnosis

Acute sinusitis is diagnosed from symptoms and examination; X-rays and CT are not needed for uncomplicated cases. For chronic or recurrent sinusitis, an ENT specialist may perform nasal endoscopy and order a CT scan to confirm inflammation and look at anatomy. Allergy testing and immune tests may be added.

Treatment

Home care and symptom relief

• saline nasal rinses or sprays, using distilled, sterile or boiled and cooled water
• steroid nasal sprays (fluticasone, mometasone, budesonide) to reduce swelling
• pain relief: acetaminophen (paracetamol) or ibuprofen, following the label dose
• steam, warm compresses and rest
• decongestant sprays for no more than 3 days; oral decongestants are not suitable with high blood pressure or heart disease
• antihistamines only if allergies contribute

Antibiotics

Antibiotics do not help viral sinusitis. For likely bacterial sinusitis, guidelines allow either a period of watchful waiting with follow-up, or antibiotics, usually amoxicillin or amoxicillin-clavulanate for 5 to 10 days. Many cases resolve without them.

Chronic sinusitis

• daily saline irrigation and steroid sprays or rinses
• short courses of oral steroids for nasal polyps
• biologic medicines (dupilumab, omalizumab, mepolizumab) for severe chronic sinusitis with nasal polyps
• endoscopic sinus surgery when medical treatment fails

Complications

Rare but serious complications include spread of infection to the eye socket (orbital cellulitis), bone, or brain (meningitis, abscess). Warning signs are eye swelling, vision changes, severe headache, stiff neck and confusion.

Prevention

• wash hands to reduce colds
• treat allergies
• avoid smoke
• use saline rinses if you are prone to sinusitis

Frequently asked questions

What are the symptoms of sinusitis?

Common symptoms are facial pain or pressure, a blocked nose, thick yellow or green mucus, post-nasal drip, reduced sense of smell, headache, cough and sometimes fever or upper tooth pain.

How long does a sinus infection last?

Viral sinusitis usually improves within 7 to 10 days. Bacterial sinusitis can last longer and may need antibiotics. Symptoms lasting 12 weeks or more indicate chronic sinusitis, which needs specialist assessment.

Do I need antibiotics for a sinus infection?

Usually not. Most sinus infections are viral and get better on their own. Antibiotics are considered if symptoms last 10 days or more, start severe with high fever, or improve then worsen.

How can I tell if my sinus infection is bacterial?

Bacterial sinusitis is more likely if symptoms last 10 days or more without improvement, begin severely with a high fever and thick discharge, or improve and then worsen. Mucus color alone does not tell the difference.

What is the fastest way to relieve sinus pressure?

Saline rinses, a steroid nasal spray, steam, warm compresses over the face, and an over-the-counter pain reliever help most. A decongestant spray can give quick relief but should not be used for more than 3 days.