Sinusitis

Rhinosinusitis is a common condition affecting the paranasal sinuses, most frequently the maxillary and ethmoid sinuses. Acute Rhinosinusitis (ARS) usually follows a viral URTI (common cold), with only 0.5–2% developing a secondary bacterial infection (Streptococcus pneumoniae, Haemophilus influenzae). Chronic Rhinosinusitis (CRS) is subdivided into CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRS is often associated with asthma, aspirin sensitivity (Samter’s Triad), and cystic fibrosis. Diagnosis is primarily clinical, based on the presence of two or more 'major' symptoms: nasal obstruction, discoloured discharge, facial pain/pressure, and reduction in the sense of smell (hyposmia/anosmia). NICE (NG133) guidelines advise against routine antibiotic use for ARS lasting less than 10 days, as most cases resolve without them. Complications, though rare, are serious and include orbital cellulitis (manifesting as proptosis or reduced eye movement), Pott’s puffy tumour (frontal bone osteomyelitis), and intracranial abscess. Management of CRS focuses on reducing mucosal inflammation through long-term intranasal steroids and saline douching. Functional Endoscopic Sinus Surgery (FESS) is reserved for cases refractory to medical therapy.

The paranasal sinuses are air-filled cavities lined with pseudostratified ciliated columnar epithelium (respiratory mucosa). Pathogenesis involves a cycle of osteomeatal complex (OMC) obstruction, impaired mucociliary clearance, and stasis of secretions. In ARS, viral infection causes mucosal oedema, blocking the narrow drainage ostia of the sinuses. This leads to hypoxia within the sinus and promotes bacterial growth. In CRS, the aetiology is more complex, involving chronic inflammatory infiltration (often eosinophilic in CRSwNP), biofilm formation, and structural changes. Nasal polyps are non-neoplastic outgrowths of the inflamed mucosa, commonly arising from the ethmoid sinuses. Their development is heavily influenced by Th2-mediated inflammation and IL-5. If a polyp is unilateral, it must be biopsied or imaged to exclude malignancy (e.g., inverted papilloma or squamous cell carcinoma).

Symptoms include nasal congestion, rhinorrhoea (often thick and yellow/green), facial pain or pressure that radiates to the teeth, and anosmia. In ARS, a fever may be present. Physical exam may reveal tenderness over the sinuses and visible pus in the middle meatus. Clinical 'red flags' requiring urgent referral include: periorbital oedema/erythema, displaced globe, double vision (diplopia), reduced visual acuity, severe unilateral headache, or frontal swelling. In CRS, nasal polyps appear as pale, translucent, insensitive 'grape-like' masses. Complications include orbital cellulitis (Stage I-V Chandler criteria), meningitis, and dural sinus thrombosis. Patients with CRS often report a significant impact on quality of life, comparable to chronic obstructive pulmonary disease or congestive heart failure.

- Bedside: Anterior rhinoscopy (using a speculum) or flexible nasendoscopy in specialist settings to look for polyps or pus.
- Bloods: Generally not indicated unless systemic sepsis is suspected.
- Imaging: CT Paranasal Sinuses (coronal, axial, and sagittal views) is the gold standard for CRS and preoperative planning, but NOT indicated for ARS. MRI if intracranial spread is suspected.
- Special tests: Allergy testing (RAST/Skin prick) if an allergic component is suspected; sweat test in children with bilateral polyps (to screen for Cystic Fibrosis).

Acute Sinusitis: Symptomatic relief with paracetamol/ibuprofen. If symptoms <10 days: no antibiotics. If symptoms >10 days: High-dose intranasal corticosteroid (e.g., Mometasone) for 14 days. If 'double sickening' or systemically unwell: Phenoxymethylpenicillin (500mg QDS for 5 days) or Co-amoxiclav. Chronic Rhinosinusitis: Long-term intranasal corticosteroids (3 months+), nasal saline irrigation (douching). For CRSwNP: Oral steroids may be used for short-term 'medical polypectomy'. Surgery: Functional Endoscopic Sinus Surgery (FESS) to restore drainage and aeration if medical management fails.