Sinusitis
Exam Tips
- Use duration plus pattern: <10 days suggests viral; >10 days or worsening after day 5 suggests post-viral; suspect bacterial if >=3 classic features (purulence, unilateral severe pain, fever >38 C, double-sickening, prolonged symptoms).
- Do not request routine imaging for uncomplicated acute sinusitis in OSCE/viva scenarios; reserve CT/endoscopy for complications, atypical disease, recurrent episodes, or surgical planning.
- Red flags needing urgent same-day ENT/emergency assessment: orbital swelling/erythema, reduced eye movements or vision, severe frontal swelling, focal neurology, meningism, altered consciousness, or severe systemic toxicity.
- In children, remember cough (day and night) with nasal obstruction/discoloured discharge is a key diagnostic cluster.
- For prescribing stations, justify antibiotic stewardship and provide safety-net advice; state contraindications clearly (e. g, doxycycline in pregnancy, NSAIDs in aspirin-exacerbated respiratory disease).
Definition
Sinusitis (more precisely rhinosinusitis) is symptomatic inflammation of the nasal mucosa and paranasal sinuses, usually presenting with nasal obstruction/discharge plus facial pressure or smell disturbance. Acute disease resolves within 12 weeks (often viral), while chronic rhinosinusitis persists for 12 weeks or longer and is driven by sustained mucosal inflammation with or without nasal polyps.
Pathophysiology
Most acute cases begin after a viral upper respiratory infection causing mucosal oedema around the ostiomeatal complex, sinus outflow obstruction, reduced oxygen tension, impaired mucociliary clearance, and retained secretions. This environment promotes secondary bacterial overgrowth in a minority of patients (commonly Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis). Chronic rhinosinusitis is a heterogeneous inflammatory disorder (type 2 eosinophilic and non-type 2 patterns), with contributions from epithelial barrier dysfunction, biofilms, ciliary impairment, and structural narrowing; polyp disease is associated with persistent type 2 cytokine activity and mucosal remodelling. Image correlation for revision: coronal CT views of the ostiomeatal complex and maxillary/ethmoid sinus opacification in standard ENT radiology figures.
Risk Factors
- Recent viral URTI (rhinovirus, RSV, parainfluenza, influenza)
- Smoking (impaired mucociliary function)
- Allergic rhinitis
- Asthma/COPD and NSAID-exacerbated respiratory disease
- Ciliary disorders (cystic fibrosis, primary ciliary dyskinesia)
- Immunodeficiency (including HIV or immunoglobulin deficiency)
- Dental infection or recent dental procedures (especially unilateral maxillary disease)
- Anatomical obstruction (septal deviation, polyps, turbinate hypertrophy, tumour, foreign body)
- Iatrogenic factors (sinus surgery, nasal packing, ventilation, NG tubes)
- Occupational/environmental exposure (e. g, pesticides, some rural/firefighting/fishing exposures)
Clinical Features
Symptoms
- Nasal blockage/obstruction/congestion
- Nasal discharge (anterior rhinorrhoea or post-nasal drip; may be discoloured)
- Facial pain/pressure or frontal/maxillary headache
- Reduced or lost sense of smell
- Cough (particularly in children, often day and night)
- Malaise, fatigue, fever, sore throat, hoarseness
- Possible dental pain (especially maxillary sinus involvement)
Signs
- Facial tenderness on gentle palpation
- Inflamed, oedematous nasal mucosa on anterior rhinoscopy
- Mucopurulent discharge in nasal cavity or post-nasal pharynx
- Associated nasal polyps or structural abnormalities (e. g, septal deviation)
- Tender maxillary dentition
- Middle ear effusion
- Pyrexia or systemic upset in more severe illness
Investigations
Management
Lifestyle Modifications
- Explain natural course: most acute cases are self-limiting; safety-net for red flags
- Hydration, rest, and regular analgesia as needed
- Saline nasal irrigation to reduce crusting and improve mucociliary clearance
- Smoking cessation advice
- Avoid unnecessary repeated oral/nasal decongestant use (risk of rebound congestion with prolonged topical use)
Pharmacological Treatment
Analgesia/antipyretics
- Paracetamol 1 g orally every 4-6 hours when required (max 4 g/day)
- Ibuprofen 200-400 mg orally up to three times daily with food (use lowest effective dose)
Check liver disease/alcohol excess for paracetamol and renal disease, peptic ulcer risk, anticoagulants, heart failure, or NSAID-sensitive asthma for ibuprofen.
Intranasal corticosteroid
- Mometasone furoate nasal spray 2 sprays into each nostril once daily (200 micrograms/day), may increase to twice daily in some protocols
- Fluticasone propionate nasal spray 2 sprays into each nostril once daily (reduce to 1 spray each nostril once controlled)
Useful particularly if symptoms persist beyond ~10 days, significant nasal inflammation, allergic component, or chronic rhinosinusitis. Advise correct spray technique and delayed onset over days.
Antibiotics for acute bacterial sinusitis (when indicated)
- Phenoxymethylpenicillin 500 mg four times daily for 5 days (1 g four times daily if severe)
- Doxycycline 200 mg on day 1, then 100 mg once daily for 4 days (adult alternative if penicillin allergy)
- Clarithromycin 500 mg twice daily for 5 days (alternative where appropriate)
- Erythromycin 250-500 mg four times daily (or 500-1000 mg twice daily) for 5 days in pregnancy if macrolide needed
- Co-amoxiclav 500/125 mg three times daily for 5 days (second choice guided by response/risk factors)
Do not prescribe routinely for likely viral illness. Consider immediate or delayed antibiotics if systemically very unwell, high risk of complications, or prolonged/worsening symptoms suggest bacterial infection. Safety: check penicillin allergy, QT-prolongation/drug interactions with macrolides, C. difficile risk, hepatotoxicity with co-amoxiclav, and avoid doxycycline in pregnancy/breastfeeding and children <12 years.
Chronic rhinosinusitis medical therapy
- Regular intranasal corticosteroid (e. g, mometasone or fluticasone as above)
- Short course oral corticosteroid in selected severe polyp disease under specialist advice (e. g, prednisolone course per ENT protocol)
Long-term antibiotics are specialist-led only; balance potential benefit against antimicrobial resistance and adverse effects.
Surgical / Interventional
- Functional endoscopic sinus surgery (FESS) for persistent symptoms despite maximal medical therapy
- Polypectomy when obstructive nasal polyps contribute to disease burden
- Drainage of orbital or intracranial abscess as emergency source control
- Address structural or odontogenic causes (e. g, septoplasty, dental source treatment) in selected patients
Complications
- Acute bacterial superinfection
- Progression to chronic rhinosinusitis
- Orbital complications: preseptal cellulitis, orbital cellulitis, subperiosteal/orbital abscess
- Intracranial spread: meningitis, epidural abscess, subdural empyema, cerebritis, brain abscess
- Osseous complications: frontal bone osteomyelitis and Pott's puffy tumour
- Major quality-of-life impairment (sleep disturbance, fatigue, mood symptoms, reduced work productivity)
Prognosis
Acute rhinosinusitis is usually self-limiting, with most patients improving without antibiotics; only a small proportion develop true acute bacterial disease. Chronic rhinosinusitis often follows a relapsing-remitting course and can substantially affect quality of life, but symptom control is achievable in many patients with regular intranasal corticosteroids, trigger management, and ENT-directed therapy when needed.
Sources & References
🏥BMJ Best Practice(4)
💊BNF Drug References(1)
- Moxifloxacin[management.pharmacological]
✅NICE Guidelines(1)
- Sinusitis[overview]