Acute Sinusitis

Acute Sinusitis

Sinusitis of less than four weeks’ duration is known as acute (short-term) sinusitis. Most of the sinusitis cases are acute sinusitis. The vast majority of acute sinusitis cases occurs primarily as a result of a preceding viral upper respiratory tract infection. It is difficult to differentiate acute bacterial and viral sinusitis clinically.

Causes of acute sinusitis

  • Infectious factors
    • Viruses (rhinovirus, parainfluenza, and influenza virus)
    • Bacteria
      • Streptococcus pneumoniae or Haemophilus influenzae (50-60 % bacterial infections)
      • Moraxella catarrhalis (in 20 % of children, but less often in adults)
      • Other streptococcal species
      • Staphylococcus aureus
      • Anaerobic bacteria
    • Fungi


  • Non-infectious factors
    • Allergic rhinitis (with either polyp obstruction or mucosal oedema)
    • Chemical irritants
    • Baro-trauma (air travel or deep-sea diving)
    • Nasal or sinus tumours
    • Altered mucous viscosity


Signs and symptoms

  • Nasal drainage or discharge (sometimes, thick, discoloured discharge)
  • Nasal congestion/blockage
  • Headache
  • Facial pain or pressure
  • Facial pain and headache (mainly, forehead or around the eyes) can be worsened, when the patient bends forward or is lying down.
  • Facial oedema
  • Cough
  • Sneezing
  • Fever
  • Sometimes, upper tooth pain



It is difficult to differentiate acute bacterial and viral sinusitis clinically. However, if symptoms of sinusitis have lasted less than seven days, acute bacterial sinusitis is unlikely. Patients with symptoms, which have lasted more than seven days, are more likely to have acute bacterial sinusitis. However, only 40-50 % of the patients, who meet this criterion, have true acute bacterial sinusitis.

CT or MRI scans are not recommended as routine investigations, particularly during initial seven days of illness. Sinus X-rays are now rarely used to visualise the sinuses. If the patient has had recurrent, persistent, or chronic sinusitis, CT or MRI scans of the sinuses are recommended.

If the patient is immunocompromised and has had an acute fungal sinusitis, immediate examination by an otolaryngologist is needed. A pathologist will examine the biopsies of the affected areas for evidence of fungi and tissue invasion. If sinusitis is recurrent or associated with complications such as orbital cellulitis, an ENT opinion is required, and CT or MRI scan may be offered.



Most of the acute sinusitis cases improve spontaneously without antibiotic treatment. If the patient has had mild to moderate symptoms of less than seven days’ duration, sinus drainage should be facilitated. Oral or topical nasal decongestants such as xylometazoline and nasal saline lavage are recommended for sinus drainage. If the patient has a history of allergies or chronic sinusitis, a topical corticosteroid nasal spray such as fluticasone propionate will be offered to reduce mucosal swelling. Steam inhalations also facilitate sinus drainage.

If the patient has had severe sinusitis (regardless of duration) or sinusitis lasted for more than seven days’ duration, antibiotic therapy (such as Co-amoxiclav) should be offered.

The patients, who do not respond to initial antibiotic treatment, may need sinus aspiration and/or lavage by an otolaryngologist. Functional endoscopic sinus surgery (FESS) is used for drainage and ventilation of the sinuses.

The patient with severe sinusitis or complications such as eye involvement and intracranial abscess, need surgical intervention and intravenous (injection) antibiotic therapy.

If the patient is immunocompromised and has had fungal sinusitis, surgical removal of fungi and intravenous antifungal drugs such as Amphotericin B are needed.



  • Baro-trauma – Trauma, which occurs due to pressure differences between the inside and outside of the body.
  • Biopsies – Tissue samples
  • CT – Computed Tomography
  • Intracranial abscess – A collection of pus in the brain
  • Lavage – Rinse or irrigation
  • MRI – Magnetic Resonance Imaging
  • Mucosal oedema – Swelling of a mucous membrane
  • Oedema – Swelling
  • Orbital cellulitis – An infection of the tissues surrounding the eye
  • Otolaryngologist – A physician, who specialises in diagnosing and treating diseases of the head and neck, especially those involving the ears, nose, and throat (ENT).
  • Pathologist – A physician, who specialises in the diagnosis and management of diseases by laboratory methods.
  • Polyp – An abnormal growth, projecting from a mucous membrane
  • Rhinitis – An inflammation of the lining of nasal cavity


(Photo courtesy: r. nial bradshaw)


Related Links:

Sinusitis (Inflammation of the Sinuses)
Chronic Sinusitis

About the author
Dr. Nalaka Priyantha is the founder and author of 'DRN Health'. He currently works at the Ministry of Health, Sri Lanka as a senior medical officer. He is blogging about healthy living since 2012.
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