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Allergies in the Nose: Sinusitis

Definition of Sinusitis

Sinusitis is a disease resulting from inflammation of the sinuses in the face. Because the nasal passages and the sinuses are linked, it is rare to have sinusitis without also suffering from rhinitis, so the disease could more appropriately be called rhinosinusitis. The sinuses are pairs of air-filled cavities in the skull; they are found below the eyes in the cheeks (the maxillary sinuses), between the eyes (the ethmoid sinuses), above the eyes (the frontal sinuses) and at the back of, and between the eyes (the sphenoid sinuses). The sinuses are lined with the same kind of mucous membrane that lines the nose. The sinuses communicate with the nose through small openings known as ostia, and in the absence of inflammation the sinuses are ventilated with each breath. 

Click here for a graphic illustrating how sinusitis causes congestion.


Acute sinusitis: Inflammation of the sinuses, with accompanying symptoms, lasting for a few weeks. This type of sinusitis often results from bacterial infection following a common cold or upper respiratory tract viral infection.

Acute recurrent sinusitis: Repeated acute sinusitis episodes occurring several times per year, for two or more years.

Chronic sinusitis: Signs and symptoms of inflammation of the sinuses persisting many weeks. The role of bacterial infection in chronic sinusitis is less clear than in acute sinusitis, and this is more typical of an inflammatory disorder.

Symptoms of Sinusitis

Symptoms of Sinusitis Include:
  • nasal congestion, or blockage,
  • large quantities of green (purulent) mucus which may be blown from the nose, or run down the back of the throat
  • cough
  • sensation of pain and fullness over the affected sinus
  • fever

Ordinary mucus is clear or light yellow. Infections cause mucus to thicken and darken. During a cold mucus often becomes dark yellow. With bacterial infections, which occur in sinusitis, the mucus can become green or dark gray.

Causes of Sinusitis

Acute sinusitis commonly begins with a cold which blocks the outflow of mucus from the sinuses, resulting in bacterial infection.

Sinusitis may be caused by benign growths in the nose called polyps. Persistent nasal congestion and loss of sense of smell can suggest the presence of polyps.

Other Common Conditions Which Can Cause, or are Associated with, Sinusitis
  • Allergic and non-allergic rhinitis
  • Anatomical abnormalities in the nose
  • Aspirin sensitivity
  • Immune system deficiencies – lack or inadequacy of antibody defense in the blood
  • AIDS
Less Common Conditions Which Cause, or are Associated with, Sinusitis
  • Cystic fibrosis
  • Bronchiectasis
  • Cocaine abuse
  • Rhinitis medicamentosa (rhinitis caused by overuse of nasal decongestants)
  • Abnormally slow and disrupted clearance of mucus from the sinuses (Ciliary dyskinesia, Kartagener’s syndrome, Young’s syndrome)
  • Wegener’s granulomatosis

How Is Sinusitis Diagnosed?

  • History of symptoms
  • Physical findings
  • Rhinoscopy – examination of the nose
  • If symptoms fail to respond to initial treatment, a computerised tomography (CT) scan of the sinuses may be recommended to confirm the diagnosis of sinusitis before different or additional therapy is initiated

Treatment of Sinusitis

Acute Sinusitis
  • Antibiotics until the patient is well. Some physicians who regularly treat acute sinusitis give antibiotics for 5-7 days after no more discolored discharge is present.
  • Decongestant twice daily for 3-7 days, applied into the nose or taken by mouth, to open and drain the sinuses
  • Oral hydration – patient recommended to drink 6 to 8 full glasses of water a day to aid mucus flow
  • Nasal washes with saline solution to clear secretions and open air communication
  • For patients with allergic rhinitis, a second-generation, non-sedating antihistamine may be included to reduce the symptoms
  • Surgery: in cases of severe acute sinusitis which has not responded to medical therapy, endoscopic surgery to remove obstructive nasal mucosa, damaged bone, mucus and pus may be recommended
Chronic Sinusitis
  • Antibiotics for a longer period of time (3-6 weeks)
  • Nasal decongestant twice daily for 7-14 days
  • Topical nasal corticosteroid to prevent rhinitis medicamentosa developing from the use of the decongestant, and to keep communication with outside air open to prevent recurrence of disease
  • Oral hydration
  • Nasal washes
Allergic Fungal Sinusitis
  • Surgery and corticosteroids
  • For invasive fungal sinusitis, antifungal treatment may be tried

Links to Additional Information on Sinusitis

American Academy of Allergy, Asthma and Immunology (AAAAI) (in Spanish)

American College of Allergy, Asthma and Immunology (ACAAI)

Australasian Society of Clinical Immunology and Allergy (ASCIA)