Acute Rhinosinusitis

Risk Factors

The main risk factors for acute rhinosinusitis include:

• Recent viral upper respiratory tract infection
• Cigarette smoke exposure (active or passive)
• Air pollution exposure
• Anatomical variations, such as septal deviation, nasal polyps, or sinus hypoplasia
• Atopic disease, such as asthma or hayfever
• Impaired mucociliary function, such as cystic fibrosis, or Kartagener’s syndrome

Clinical Features

Acute rhinosinusitis is distinguished from chronic rhinosinusitis by the duration of symptoms. Symptoms lasting less than 12 weeks are classified as acute rhinosinusitis. Episodes are more common in the winter months.

The diagnosis of acute rhinosinusitis requires the sudden onset of two or more of the following symptoms (<12 weeks):

• Nasal blockage or congestion
• Discoloured nasal discharge (either anterior or posterior discharge)
• Facial pain or pressure (usually unilateral over the maxillary or frontal sinus)
• Altered or loss sense of smell

Symptoms that may suggest a bacterial cause include severe local pain, discoloured discharge, fever, or worsening after an initial improvement (post-viral).

Any presence of alarm symptoms should trigger an immediate referral to specialist care. These include periorbital oedema/erythema, displaced globe, double vision, ophthalmoplegia, reduced visual acuity, severe headache, frontal swelling, signs of sepsis/meningitis, neurological signs.

Differential Diagnosis

The main differential diagnoses for acute rhinosinusitis include:

• Viral upper respiratory tract infection –  symptoms tend to improve with symptomatic treatment within 3-5 days
• Allergic rhinitis – should be suspected where there is a history of allergy or atopy, and symptoms include other allergic features; mucopurulent discharge or loss of sense of smell are unlikely
• Facial pain syndromes – includes diagnosis such as migraines, cluster headaches, or mid-segment facial pain; the absence of other nasal symptoms make these diagnoses more likely
• Nasal foreign body – causes a unilateral mucopurulent discharge or blockage; more common in children

Investigations

The diagnosis of acute rhinosinusitis is typically made on clinical symptoms alone. Imaging, such as a CT scan (Fig. 3), may be required if complications are suspected.

Skin prick testing for allergy might be appropriate in patients with recurrent episodes and symptoms suggested of allergic rhinitis.

By BioMed Central Ltd [CC BY SA 2.0], via PubMed Central

Figure 3
CT scan demonstrating left maxillary sinus opacification, which is typically seen in rhinosinusitis

Management

Most cases of acute rhinosinusitis cases can be managed in the community, and do not require treatment with antibiotics, as they are viral in origin. The aim of treatment is to reduce inflammation of the nasal mucosa and improve the drainage of the paranasal sinuses.

Initial Management

For uncomplicated acute rhinosinusitis without features of bacterial infection, treatment with analgesia, saline nasal douche and nasal decongestants will suffice. For those with signs of acute bacterial rhinosinusitis (e.g. purulent discharge or fever*), antibiotics are indicated. If symptoms are not improving after 10 days, or increased after 5 days, steroid nasal sprays can be given.

If there is no improvement after 7-14 days of treatment or the presence of red-flag symptoms (as listed above), referral to ENT services should be considered.

*A common sign of a bacterial infection is “double sickening”, where the patient worsens after a preceding mild phase of illness

Specialist Management

An ENT specialist will perform nasal endoscopy, to identify any abnormal anatomy or pathology. A culture of any nasal discharge may be warranted for atypical infections.

A CT scan of the paranasal sinuses would show the extent of the disease, as well as identifying complications (see below) and any underlying anatomical abnormalities.

For severe infections or complications, admission might be necessary for treatment with oral steroids, intravenous antibiotics, and the consideration of surgery.

Complications

Potential complications of acute rhinosinusitis include:

• Periorbital cellulitis – sinusitis is the commonest cause of periorbital cellulitis (Fig. 4)
• Orbital cellulitis or abscess – infection can extend into the eye causing orbital cellulitis
• Osteomyelitis – infection invading the bone can eventually lead to penetration into the skull vault causing intracerebral complications
• Pott’s Puffy tumour – osteomyelitis of the frontal sinus can result in a soft boggy swelling over the overlying tissue on the forehead (Fig. 5)
• Intracranial abscess or venous sinus thrombosis.

By Phillip T. Suwan et al. [CC BY SA 2.0], via PubMed Central

Figure 5
Pott’s puffy tumour. A) Child demonstrating a notable amount of fullness over the area corresponding to the frontal sinus. B) Axial CT of the brain demonstrating subperiosteal (arrow) and epidural abscesses (circle).