Key Facts

Nasal polyps are benign inflammatory growths of the nasal and paranasal sinus mucosa. They are a common manifestation of chronic rhinosinusitis and are associated with asthma, aspirin sensitivity, and cystic fibrosis. They cause nasal obstruction and anosmia and often require combined medical and surgical management.

Epidemiology

• Prevalence: 1-4% of the general population
• Male:female ratio 2:1
• Peak onset: >40 years; rare in children (if present, investigate for cystic fibrosis)
• Present in 20-50% of patients with asthma; 60-70% of patients with aspirin-exacerbated respiratory disease (AERD)

Aetiology

• Chronic eosinophilic inflammation of the sinonasal mucosa
• Associated conditions: chronic rhinosinusitis, asthma, allergic fungal rhinosinusitis, AERD (Samter's triad), cystic fibrosis, primary ciliary dyskinesia (Kartagener syndrome), Churg-Strauss syndrome (EGPA)
• Type 2 inflammation: IL-4, IL-5, IL-13 driven eosinophilic infiltration
• Not caused by allergy per se, but allergic rhinitis is a common comorbidity

Pathophysiology

• Chronic inflammation leads to oedematous thickening of the sinus mucosa
• Prolapse of oedematous mucosa through sinus ostia into the nasal cavity
• Eosinophilic infiltration predominates; driven by type 2 cytokines (IL-5, IL-13)
• Epithelial barrier dysfunction and Staphylococcus aureus superantigens contribute
• Polyps cause mechanical obstruction, impaired mucociliary clearance, and olfactory dysfunction
• Recurrence after surgical removal is common due to underlying mucosal disease

Symptoms

• Nasal obstruction (bilateral, progressive)
• Anosmia/hyposmia (often the most troublesome symptom)
• Nasal discharge (mucoid or mucopurulent)
• Post-nasal drip
• Facial pressure/fullness
• Snoring
• Headache (if sinus involvement)

Examination

• Anterior rhinoscopy/nasal endoscopy: pale, grey, smooth, glistening, insensitive, pedunculated masses
• Bilateral in most cases
• Originate from middle meatus (ethmoid sinus mucosa)
• Do NOT bleed on touch or cause pain (insensitive — distinguishes from turbinates)

Red Flags

• Unilateral polyp in adult — biopsy to exclude inverted papilloma or malignancy
• Nasal polyps in a child — investigate for cystic fibrosis (sweat test)
• Bloodstained discharge or friable tissue (malignancy)
• Facial deformity or proptosis (aggressive lesion)
• Anosmia with polyps and asthma — consider AERD/Samter's triad

Bedside

• Anterior rhinoscopy and nasal endoscopy
• Assessment of nasal airflow
• Smell testing

Bloods

• Total IgE and specific IgE (allergic component)
• Eosinophil count (type 2 inflammation marker)
• Aspergillus-specific IgE (allergic fungal rhinosinusitis)
• Sweat test: if polyps in a child (cystic fibrosis screening)
• ANCA: if vasculitis suspected (EGPA)

Imaging

• CT paranasal sinuses (non-contrast): gold standard
  • Mucosal thickening, opacification, polypoidal changes
  • Lund-Mackay score for severity grading
  • Pre-operative planning for FESS
• MRI: if complications, malignancy, or skull base involvement suspected

Special Tests

• Nasal peak inspiratory flow (NPIF): objective measure of nasal airflow
• SNOT-22 questionnaire: validated quality of life measure for rhinosinusitis
• Biopsy: for unilateral polyps (exclude malignancy/inverted papilloma)
• Skin prick testing: for allergic rhinitis assessment

Non-pharmacological

• Saline nasal irrigation (daily, large-volume — NeilMed, sterile saline)
• Allergen avoidance if allergic component identified
• Smoking cessation

Pharmacological

• First-line: intranasal corticosteroid drops or spray:
  • Mometasone 200mcg each nostril OD or fluticasone 200mcg each nostril OD
  • Betamethasone 0.1% drops (head-down position) — more effective for polyps than sprays
  • Long-term maintenance therapy
• Short course oral prednisolone: 25-30mg OD for 5-10 days
  • For significant polyp load, acute exacerbation, or pre-operatively (to shrink polyps)
  • Limit to 2-3 courses per year (steroid side effects)
• Biologics (for severe CRSwNP refractory to steroids and surgery):
  • Dupilumab (anti-IL4Rα): SC injection, NICE TA851 approved
  • Mepolizumab (anti-IL5): for severe eosinophilic CRSwNP
  • Omalizumab (anti-IgE): if concurrent allergic asthma
• Antihistamines: if concurrent allergic rhinitis
• Aspirin desensitisation: for AERD (specialist centre)

Surgical

• FESS (functional endoscopic sinus surgery) with polypectomy:
  • Indicated when polyps refractory to maximal medical therapy (≥8 weeks of intranasal steroids + at least one course of oral steroids)
  • Removes polyps and opens sinus ostia to improve drainage and topical steroid access
  • Success rate for symptom improvement: 80-90%
• Revision FESS: for recurrent polyps (recurrence rate 20-40% at 5 years)

Referral Criteria

• ENT referral: nasal polyps visible on examination, chronic rhinosinusitis not responding to 3 months of medical therapy
• Urgent/2-week wait: unilateral polyp (exclude malignancy), bloodstained discharge
• Paediatric: nasal polyps in child (cystic fibrosis investigation)

• Nasal polyps are a chronic condition with high recurrence after treatment
• Intranasal steroids: reduce polyp size and improve symptoms in >60%
• Oral steroids: rapid but temporary reduction in polyp size
• Post-FESS: 80-90% symptom improvement; 20-40% polyp recurrence at 5 years
• Biologics: significant improvement in polyp score, smell, and QoL in refractory patients
• AERD/Samter's triad: more aggressive disease, higher recurrence rates
• Anosmia: may not fully recover despite treatment
• Long-term follow-up required with serial nasal endoscopy and SNOT-22 scoring

Nasal Polyp Grading (Lildholdt Scale)

Samter's Triad (AERD)

When to Investigate for Cystic Fibrosis