Sinusitis in adults: duration, symptoms, and treatment

Sinusitis refers to the inflammation and swelling of the lining that covers the sinuses. Normally, the sinuses produce mucus that drains into the nose. When this lining swells — due to infection or irritation — drainage is blocked, mucus builds up, and the sinuses become a breeding ground for bacteria.

Several forms of sinusitis are distinguished by their duration:

- Acute sinusitis symptoms that last less than four weeks. This is the most common form, often following a cold.
- Subacute sinusitis Between four and twelve weeks.
- Chronic sinusitis symptoms lasting more than twelve weeks, with or without nasal polyps.
- Recurrent sinusitis Several acute episodes per year, with a return to normal between episodes.

The sinuses most often affected are the maxillary sinuses (located in the cheeks), the frontal sinuses (above the eyebrows), and the ethmoid sinuses (between the eyes).

Causes and risk factors

The vast majority of acute sinusitis cases are viral in origin—the same viruses responsible for the common cold (rhinoviruses, coronaviruses, adenoviruses). In this case, antibiotics are of no use.

Bacterial sinusitis can occur when bacteria take advantage of sinus blockage to multiply. The most common bacteria involved are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

Other causes and contributing factors:
– Nasal allergies (allergic rhinitis) — chronic inflammation of the mucous membranes promotes sinus episodes
Nasal polyps — these growths can mechanically block the sinuses
Deviated septum — a particular anatomy can reduce natural drainage
- Tobacco smoke—irritates mucous membranes and impairs ciliary drainage.
Scuba diving, swimming in pools — pressure and chlorinated water can irritate sinuses
– Weakened immune system — increases the risk of recurrent infections

People with asthma, cystic fibrosis, or immune deficiencies are at higher risk for severe or recurrent sinusitis.

How does sinusitis manifest in adults?

Typical symptoms of acute sinusitis include:

– Facial pain or pressure — often located in the cheeks, forehead, around the eyes, or nose
– Nasal congestion — stuffy nose, difficulty breathing through the nose
– Nasal discharge — thick, often yellowish-green, sometimes flowing to the back of the throat (postnasal drip)
– Reduction or loss of smell
– Cough – often worse at night, caused by postnasal drip
– General fatigue
– Sometimes: mild to moderate fever, toothache in the upper molars (related to the maxillary sinuses)

What suggests a bacterial origin rather than viral:
– Symptoms that have lasted more than ten days without improvement
– Symptoms that worsen after initial improvement (so-called «double wave» worsening)
High fever with intense facial pain and purulent discharge

These clinical criteria guide the physician in their decision of whether or not to treat with antibiotics.

Diagnosis: When to see a doctor

Most viral sinusitis resolves in one to two weeks without any treatment other than symptomatic relief. However, medical consultation is recommended in the following situations:

– Symptoms last more than ten days with no sign of improvement
– The symptoms were improving and then suddenly worsened
You have a high fever with significant facial pain.
You have a history of recurrent bacterial sinusitis.
You have symptoms on only one side of your face, which may indicate another pathology
– Do you suffer from asthma, severe allergies, or a weakened immune system

The doctor performs a clinical examination—inspecting the throat and ears, and percussing the sinuses—to guide the diagnosis. In cases of recurrent or chronic sinusitis, an ENT referral and imaging (CT scan of the sinuses) may be necessary.

Seek immediate medical attention or call 9-1-1 if you experience: high fever with a stiff neck, swelling around an eye, blurred vision, mental confusion, or severe headache. These signs can indicate a rare but serious complication (meningitis, orbital cellulitis).

Treatment Options

For viral sinusitis—the most common type—treatment aims to relieve symptoms while the body fights the infection:

– Topical nasal decongestants (nasal sprays based on xylometazoline or oxymetazoline) — to be used for a maximum of three to five days to avoid the rebound effect
– Nasal rinses with physiological serum (isotonic saline solution) — help clear the sinuses, with no adverse effects
– Pain relievers (acetaminophen, ibuprofen) — to relieve facial pain and fever
– Nasal corticosteroids (fluticasone, mometasone) — can reduce inflammation, particularly useful in cases with an allergic component

These treatments are available over-the-counter at the pharmacy. A pharmacist can advise you on the appropriate options for your situation.

When clinical criteria indicate bacterial sinusitis, a doctor may prescribe antibiotics. Amoxicillin is often the first-line treatment. In case of penicillin allergy or resistance, other antibiotics may be used.

The duration of antibiotic treatment varies by severity. It is essential to complete the prescribed treatment, even if symptoms improve before the end.

Antibiotics are not indicated for viral sinusitis. Their inappropriate use contributes to antimicrobial resistance, a major public health problem.

For chronic or recurrent sinusitis, a more specialized approach is necessary: long-term nasal corticosteroids, immunotherapy for underlying allergies, or in some cases, endoscopic sinus surgery (FESS) to improve sinus drainage.

Access to a doctor for sinusitis

Sinusitis is a common reason for seeking medical attention that can often be assessed via telehealth, especially for uncomplicated cases. A doctor can evaluate your symptoms, determine if it's viral or potentially bacterial sinusitis, and guide you to the appropriate treatment—without you having to travel.

Clinique Omicron offers medical consultations for ENT infections, including sinusitis, via teleconsultation and at its service points in Quebec. If a physical examination or an ENT referral is necessary, our doctors can direct you quickly.

FAQ — Adult Sinusitis

How long does a viral sinus infection last?
Most viral sinus infections last seven to fourteen days. If symptoms persist beyond ten days without improvement, a medical evaluation is indicated to determine if there is a bacterial component.

Are antibiotics needed to treat sinusitis?
No, in the majority of cases. Sinusitis is most often viral, and antibiotics have no effect on viruses. They are reserved for cases that meet specific clinical criteria suggesting a bacterial infection.

Are nasal decongestants dangerous?
Topical decongestants (sprays) are effective in the short term, but their use should not exceed three to five days due to the risk of rebound effect (medicamentosa rhinitis). Oral decongestants are contraindicated in cases of high blood pressure or heart problems.

Can I have a televisit for sinusitis?
Yes, for uncomplicated cases. The doctor can assess your symptoms, guide you on symptomatic treatment, and prescribe antibiotics if the criteria warrant it.

Can sinusitis become chronic?
Yes. A sinus infection is considered chronic when symptoms persist for more than twelve weeks. It requires further evaluation, often by an ENT specialist.

How to relieve sinus pain at home?
Nasal rinses with saline solution, hot steam inhalations, applying warm compresses to the face, and pain relievers like acetaminophen or ibuprofen can help relieve symptoms.

Can sinusitis cause toothaches?
Yes. The maxillary sinuses are located just above the roots of the upper teeth. Maxillary sinusitis can cause tooth pain, especially in the upper molars.

Teleconsultation in Quebec — Private Online Doctor | Omicron Clinic