Diagnosis of uncomplicated acute rhinosinusitis

Rhinosinusitis refers to inflammation of the nasal mucosa and the paranasal sinuses. Although the term ‘sinusitis’ is commonly used to describe this condition, the term ‘rhinosinusitis’ is used in these guidelines because inflammation of the paranasal sinuses (sinusitis) usually occurs concurrently with inflammation of the nasal mucosa (rhinitis)Fokkens, 2020. Rhinitis can occur in isolation and is usually caused by an allergy – see Allergic rhinitis in the Respiratory guidelines for management.

Uncomplicated acute rhinosinusitis (often called ‘the common cold’) is one of the most common presentations in primary care in AustraliaMorcom, 2016. Patients present with 2 or more of the following features:

  • nasal blockage (congestion or obstruction)
  • nasal discharge (anterior or posterior nasal drip)
  • facial pain or pressure
  • reduction or loss of sense of smell.

Uncomplicated acute rhinosinusitis is usually self-limiting; symptoms tend to increase after 5 days but resolve within 7 to 14 days. In approximately 10% of adults and 20 to 60% of children, symptoms can persist for longerFokkens, 2020Lemiengre, 2018. If symptoms persist for longer than 12 weeks, the condition is termed chronic rhinosinusitis – see Chronic rhinosinusitis in the Respiratory guidelines for management.

Uncomplicated acute rhinosinusitis is usually caused by a viral infection. Less than 2% of patients develop a secondary bacterial infection. Primary bacterial infection is rare, but can occur in patients with odontogenic infection, deficient mucociliary clearance mechanisms (eg cystic fibrosis), mechanical nasal obstruction or immune compromiseFokkens, 2020.

Diagnosis of uncomplicated acute rhinosinusitis is based on clinical features and does not require investigations (eg chest X-ray, computed tomography [CT]).

Acute rhinosinusitis is considered complicated if the infection spreads beyond the paranasal sinuses and nasal cavity into adjacent spaces (eg meninges, ocular space, periorbital space). Assess patients early in the course of the illness for spread of infection – see Complicated acute rhinosinusitis for features and management. For patients with immune compromise and symptoms of rhinosinusitis (eg facial pain, nasal congestion, fever), maintain a high degree of suspicion for acute invasive fungal rhinosinusitis.

Uncomplicated acute rhinosinusitis is considered recurrent when patients have 4 or more distinct episodes per year without persistent symptoms between episodes – see Recurrent acute rhinosinusitis for managementFokkens, 2020.