Overview

Sinusitis is the inflammation of the mucosa of the nasal cavity and paranasal sinuses. It is also known as rhinosinusitis, as the nose is often involved as well. Sinusitis can be classified as:

  • Acute: infection lasting 7-30 days
  • Subacute: inflammation lasting 4-12 weeks
  • Recurring: >3 acute and discrete episodes lasting ≥10 days in a year
  • Chronic: symptoms persist >90 days

Most cases are caused by viral infection. The most common bacterial causes are Streptococcus pneumoniae and Haemophilus influenzae.

Epidemiology

  • Acute sinusitis is common and has a prevalence as high as 15%
  • Acute sinusitis is less common in children

Risk Factors

  • Viral upper respiratory tract infection
  • Allergic rhinitis
  • Smoking
  • Asthma
  • Anatomical variation
  • Mechanical obstructions e.g. deviated septum, polyps etc. 

Presentation

Patients usually have facial pain over the affected sinuses. Features are:

  • Facial pain/pressure
    • The pain may be worse bending forward
    • The pain may be reproduced by palpating the part of the face overlying the sinuses
  • Nasal discharge – usually purulent
  • Nasal congestion

Other features are:

  • Symptoms lasting <10 days suggest acute viral sinusitis
  • Symptoms lasting >10 days but <4 weeks suggest acute bacterial sinusitis
  • Symptoms that are severe at onset suggest acute bacterial sinusitis
  • Fever >38ºC suggests bacterial sinusitis
  • Symptoms worsen after initial improvement:
    • Known as “double-sickening”
    • This suggests a secondary bacterial infection

Differential Diagnoses

Chronic sinusitis

  • Symptoms last longer than 12 weeks

Allergic rhinitis

  • Symptoms are usually after exposure to an allergen such as pollen or animal fur
  • Patients have sneezing, rhinorrhoea, and itchy eyes
  • Facial pain and pressure are less commonly seen

Diagnosis and Referral

All patients

  • Diagnosis is clinical – based on the history and examination, including rhinoscopy

Referral

Management

Symptoms duration <10 days

  • 1st-line: self-care and consider trialling nasal saline
  • Patients should return if symptoms do not improve within 3 weeks, worsen, or they become systemically unwell

Symptoms >10 days with no improvement

  • 1st-line: high-dose corticosteroid nasal spray
  • Consider backup antibiotic prescription

Antibiotic indications

If the patient has systemic symptoms that are not life-threatening and do not warrant hospital admission, offer antibiotics:

  • 1st-line: phenoxymethylpenicillin for 5 days
  • If very unwell/high risk of complications/severe: co-amoxiclav
  • If penicillin-allergic: clarithromycin

Patient Advice

  • Patients should seek help if:
    • Symptoms suddenly worsen
    • Symptoms do not improve after 3 weeks
    • They become systemically very unwell
  • Patients should avoid smoking, swimming, and alcohol to reduce the risk.

Complications

Prognosis

  • Viral acute sinusitis usually takes around 2-3 weeks to resolve and bacterial complication occurs in around 2 in 100 cases 

Author