Chronic Rhinosinusitis (CRS)
Sinonasal inflammation ≥12 weeks, subclassified by polyp status; managed with topical therapy and surgery.
Also known as: chronic sinusitis, CRS, chronic rhinosinusitis with polyps, CRSwNP, CRSsNP
Overview
Symptomatic inflammation of the nose and paranasal sinuses for ≥12 consecutive weeks, with objective evidence of inflammation on nasal endoscopy or CT imaging. Subclassified as CRS with nasal polyps (CRSwNP) or without (CRSsNP).
Epidemiology
Affects 5-12% of US adults. CRSwNP accounts for ~20-30% of cases and is associated with asthma (especially aspirin-exacerbated respiratory disease — Samter triad). Female-to-male ratio for CRSsNP slightly female-predominant; CRSwNP male-predominant.
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Risk factors
- Allergic rhinitis, asthma
- Aspirin/NSAID sensitivity (Samter triad: nasal polyps + asthma + aspirin sensitivity)
- Cystic fibrosis, primary ciliary dyskinesia
- Immunodeficiency (CVID, IgA deficiency, HIV)
- Gastroesophageal reflux
- Smoking, air pollutants
- Anatomic obstruction (deviated septum, concha bullosa, polyps)
- Dental disease (odontogenic CRS)
Pathophysiology
Persistent mucosal inflammation impairs mucociliary clearance and sinus drainage. CRSsNP shows neutrophilic Th1/Th17 infiltrate. CRSwNP demonstrates eosinophilic Th2-driven inflammation with elevated IL-4/IL-5/IL-13 — the target of newer biologics. Bacterial biofilms and fungal colonization may perpetuate disease.
Clinical presentation
Symptoms
- ≥2 of the following for ≥12 weeks: mucopurulent drainage, nasal obstruction, facial pain/pressure/fullness, decreased smell (anosmia/hyposmia is hallmark of CRSwNP)
- Postnasal drip with chronic throat clearing or cough
- Headache, ear fullness, dental discomfort
- Fatigue, halitosis, reduced quality of life
Signs / physical exam
- Nasal endoscopy: mucopurulent discharge from middle meatus, edema/erythema, or polyps (pale gray grape-like)
- Polyps visible on anterior rhinoscopy in CRSwNP
- Hyposmia on bedside smell testing
- Cobblestoned posterior pharynx from postnasal drip
- Possible facial tenderness on palpation
Classic findings
CRSwNP: anosmia + bilateral pale polyps + asthma history (consider Samter if ASA-sensitive). CRSsNP: facial pressure + mucopurulent discharge without polyps.
Differential diagnosis
- Recurrent acute rhinosinusitis — ≥4 discrete episodes/year with full resolution between, total <12 weeks symptomatic; treat each episode and evaluate predisposing factors
- Allergic rhinitis — No CT mucosal disease; itching, sneezing, atopic history; intranasal steroid
- Nonallergic rhinitis — Trigger-related symptoms without IgE sensitization or sinus inflammation
- Allergic fungal rhinosinusitis — CRSwNP with thick allergic mucin containing fungal hyphae, hyperdense CT material, often unilateral expansion; surgery + topical steroids ± systemic
- Granulomatosis with polyangiitis (GPA) — Saddle-nose deformity, ulcers, crusts, lung involvement; positive c-ANCA/PR3
- Sarcoidosis — Strawberry-like nasal mucosa, multisystem involvement, elevated ACE, noncaseating granulomas
- Sinonasal malignancy — Unilateral persistent symptoms, epistaxis, facial numbness, mass on endoscopy; imaging and biopsy
- Cystic fibrosis — Childhood-onset CRS, nasal polyps in pediatric patient → sweat chloride test
- Primary ciliary dyskinesia — CRS + bronchiectasis + situs inversus (Kartagener); nasal nitric oxide low, biopsy of cilia
Diagnostic workup
Diagnostic criteria
AAO-HNS 2015: symptoms ≥12 consecutive weeks consistent with CRS (≥2 of mucopurulent discharge, obstruction, facial pain/pressure, decreased smell) PLUS documented inflammation on endoscopy (purulent mucus or polyps in middle meatus, mucosal edema) OR CT (paranasal sinus mucosal thickening or opacification).
Labs
- Allergy testing (skin prick or specific IgE) if concurrent allergic rhinitis suspected
- Sweat chloride and/or CF genetic testing in pediatric CRSwNP or chronic refractory CRS
- Immunoglobulin levels (IgG/IgA/IgM) and vaccine response titers in recurrent infections
- Total IgE, peripheral eosinophil count — biomarkers for biologic candidacy in CRSwNP
- ANCA, ACE if vasculitis or sarcoidosis suspected
Imaging
- CT sinus without contrast — defines mucosal disease extent, anatomic variants, surgical planning. Lund-Mackay score quantifies severity
- MRI if intracranial extension or sinonasal mass suspected
- Nasal endoscopy (clinic) — direct visualization confirms inflammation; biopsy for masses or unilateral disease
Diagnostic algorithm
| Feature | CRSsNP | CRSwNP |
|---|---|---|
| Polyps on endoscopy | Absent | Present (bilateral typical) |
| Anosmia | Less common | Hallmark feature |
| Asthma association | Sometimes | Strong (esp. AERD/Samter) |
| Inflammation type | Neutrophilic (Th1/Th17) | Eosinophilic (Th2) |
| Response to topical steroid | Moderate | Often robust |
| Biologics | Not indicated | Dupilumab, omalizumab, mepolizumab for refractory |
| Surgery role | Adjunct when medical fails | Common; high recurrence without ongoing topical therapy |
Treatment
First-line
- Saline nasal irrigation — high-volume, low-pressure with neti pot or squeeze bottle daily
- Intranasal corticosteroid — fluticasone, mometasone, budesonide — daily long-term; consider budesonide nasal rinse for refractory CRSwNP
- Treat comorbidities: allergic rhinitis (oral or intranasal antihistamine), asthma (controller), GERD
- Short course of oral corticosteroids (prednisone 0.5-1 mg/kg × 5-10 days) for severe symptoms or polyp shrinkage
- Targeted antibiotics — amoxicillin-clavulanate or doxycycline × 3 weeks — only during acute bacterial exacerbations
Second-line / adjunct
- Functional endoscopic sinus surgery (FESS) — for failure of medical therapy, recurrent acute exacerbations, polyps, or complications
- Aspirin desensitization for Samter triad — improves polyp control and reduces revision surgery
- Biologics for severe CRSwNP refractory to surgery and topical therapy — dupilumab (anti-IL-4Rα), omalizumab (anti-IgE), mepolizumab (anti-IL-5)
- Long-term low-dose macrolide (azithromycin) — immunomodulatory; limited evidence in CRSsNP
- Allergy immunotherapy if allergic component is dominant
Complications
- Persistent QoL impairment, work/school disability
- Acute bacterial exacerbations
- Orbital and intracranial extension (mucocele, abscess) — less common than in acute disease but possible
- Mucocele formation (especially frontal sinus)
- Anosmia, dysosmia
- Worsening asthma control
- Sinonasal squamous cell carcinoma or inverted papilloma should be considered with unilateral persistent disease
PANCE pearls
- Unilateral chronic sinusitis is a red flag — image and biopsy to exclude tumor, fungal disease, or odontogenic source.
- CRSwNP with asthma + aspirin sensitivity = Samter triad (aspirin-exacerbated respiratory disease, AERD).
- Anosmia points strongly toward polyposis — examine the nose carefully.
- Avoid prolonged systemic antibiotics — topical therapy and surgery are more durable.
- Pediatric polyposis demands CF workup — sweat chloride test.
References
- AAO-HNS 2015 — Rosenfeld RM et al. Clinical Practice Guideline (Update): Adult Sinusitis. Otolaryngol Head Neck Surg 2015;152(2S):S1-S39
- ICAR-RS 2021 — Orlandi RR et al. International Consensus Statement on Allergy and Rhinology: Rhinosinusitis 2021. Int Forum Allergy Rhinol 2021;11(3):213-739
- EPOS 2020 — Fokkens WJ et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology 2020;58(S29):1-464
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