What is the best treatment approach for a patient with Chronic Rhinosinusitis (CRS), potentially with comorbid allergies or asthma?

Treatment of Chronic Rhinosinusitis (CRS)

Intranasal corticosteroids combined with daily saline nasal irrigation form the cornerstone of CRS management, with this regimen providing the strongest evidence for symptom control and should be initiated as first-line therapy for all patients. 1, 2, 3

Initial Assessment and Diagnosis

Before initiating treatment, confirm the diagnosis with objective evidence of inflammation:

• Document sinonasal inflammation using anterior rhinoscopy or nasal endoscopy to visualize polyps, purulence, or mucosal swelling 1, 2
• Confirm presence or absence of nasal polyps as this fundamentally alters treatment approach and prognosis 1
• Assess for comorbid conditions including asthma, cystic fibrosis, immunocompromised state, and ciliary dyskinesia, as these modify management 1
• Evaluate for allergies through skin prick testing or serum-specific IgE, particularly for perennial allergens (dust mites, pet dander, mold, cockroaches) 1, 4

Common pitfall: Failing to confirm diagnosis with objective evidence leads to misdiagnosis and inappropriate treatment. 2

First-Line Medical Management (All CRS Patients)

Core Therapy

• Intranasal corticosteroids (e.g., fluticasone propionate): Use daily, as these work on multiple inflammatory mediators beyond histamine alone and reduce airway hyperresponsiveness 1, 2, 5
• Saline nasal irrigation: Perform daily to remove irritants, reduce congestion, and improve medication delivery 1, 2, 3

This combination has Grade A evidence and should be maintained long-term for symptom control. 3

Treatment Based on CRS Phenotype

CRS Without Nasal Polyps (CRSsNP)

For mild symptoms:

• Continue intranasal corticosteroids and saline lavage 2, 6
• Monitor response for 3 months 2

For moderate-to-severe or refractory symptoms after 3 months:

• Culture-directed antibiotic therapy if purulence is present 2
• Long-term macrolide antibiotics (highest evidence for this phenotype) 6
• Consider short course of oral corticosteroids 2
• Obtain CT imaging to assess disease extent 2

CRS With Nasal Polyps (CRSwNP)

• Higher potency intranasal corticosteroids or increased dosing 2
• Short course of oral corticosteroids (e.g., prednisone) to reduce polyp burden 2, 7, 6
• Topical steroid irrigations (highest evidence for CRSwNP) 6
• Consider aspirin desensitization therapy (ATAD) for aspirin-intolerant patients 1, 6

For patients with type 2 inflammation and inadequate response to medical therapy:

• Biologic therapy should be considered, with dupilumab preferred for CRSwNP based on network meta-analysis 1
• Mepolizumab is preferred for CRSwNP with highly eosinophilic asthma 1
• Biologics are indicated for patients with history of sinus surgery and ≥3 of the following: evidence of type 2 inflammation, need for systemic corticosteroids, significantly impaired quality of life 1

Management of Comorbid Conditions

Asthma and CRS

The relationship is bidirectional—treating CRS improves asthma control and reduces need for asthma medications. 1

• Assess all CRS patients for asthma, particularly those with severe or difficult-to-control disease 1
• 84-100% of patients with severe asthma have abnormal sinus CT findings 1
• Endoscopic sinus surgery improves asthma control and decreases exacerbations and corticosteroid use in asthmatics 1
• For combined CRSwNP and asthma, biologics targeting type 2 inflammation (dupilumab, mepolizumab, or tezepelumab) are recommended 1

Allergic Rhinitis and CRS

• Prevalence of allergic rhinitis is 40-84% in adults with CRS 1
• Treat allergic rhinitis with intranasal corticosteroids as first-line 1
• Add oral second-generation antihistamines for sneezing and itching 1
• Allergen immunotherapy (subcutaneous or sublingual) should be offered for patients with inadequate response to pharmacotherapy 1, 4

Common pitfall: Overlooking allergic components that could be effectively managed with targeted therapy. 2

Surgical Intervention

Refer to otolaryngology for surgical evaluation when:

• Medical management fails after appropriate 3-month trial 2
• Disease is advanced with polyps, osteitis, bony erosion, or fungal involvement 2
• Alarm symptoms are present 8
• Patient has refractory symptoms despite optimal medical therapy 2, 3

Functional endoscopic sinus surgery provides an adjunctive therapeutic option but does not cure CRS—maintenance medical therapy remains necessary postoperatively. 3

Treatments to Avoid

• Do not use antifungal therapy for routine CRS management (not recommended) 2
• Do not routinely prescribe antibiotics without evidence of bacterial infection 2
• Do not offer oral leukotriene receptor antagonists as primary therapy for allergic rhinitis component 1

Special Considerations for Immunodeficiency

Consider immunologic testing when:

• Aggressive management has failed 1
• CRS is associated with recurrent otitis media, bronchiectasis, or pneumonia 1
• Testing may include quantitative immunoglobulin assays and specific antibody responses to polysaccharide vaccines 1, 2

Common variable immunodeficiency is found in 10% of patients with refractory CRS, and IgA deficiency in 6%. 1

Treatment Algorithm Summary

1. Confirm diagnosis with nasal endoscopy or CT showing inflammation 1, 2
2. Identify phenotype (with/without polyps) and assess for comorbidities (asthma, allergies) 1
3. Initiate first-line therapy: intranasal corticosteroids + saline irrigation for all patients 1, 2
4. After 3 months, if inadequate response:
   • CRSsNP: Add culture-directed antibiotics or long-term macrolides 2, 6
   • CRSwNP: Add oral corticosteroids, consider biologics if type 2 inflammation present 1, 2
5. Refer to ENT if medical management fails or alarm symptoms present 2, 8
6. Maintain therapy long-term even after symptom improvement to prevent exacerbations 5, 3