Inclusion Criteria:

1. Ages 18-65;
2. Meet clinical definition of CRS, which is 12 weeks with at least 2 of the major criteria for diagnosis (nasal discharge, nasal obstruction, facial congestion, facial pain-pressure-fullness, or a decrease in smell) within the past 24 months
3. Have a sinus CT scan within the past 24 months with a Lund-Mackay score >5
4. Nasal polyps must be documented within the past 3 years on physical exam and endoscopy

Normal controls are healthy individuals with no history of allergy or CRS, normal spirometry, and negative skin prick test results or negative IgE serum tests to 6 common aeroallergens, including house dust mite, Alternaria, cat/dog dander, ragweed, orchard grass, and oak. 

Exclusion Criteria:

1. Cystic fibrosis
2. Primary ciliary dyskinesia
3. Immune deficiency disorders
4. Current cigarette smoking >1 cigarette/day
5. Oral corticosteroids or high-dose inhaled corticosteroids in the past 6 weeks before enrollment
6. On any biologics treatment
7. A lower or upper airway infection (e.g., ‘cold’) in the last 4 weeks.
8. Pregnant women
9. Prisoners
10. CRS patients without nasal polyps or with other underlying medical illnesses that accompany chronic sinusitis (primary ciliary dyskinesia, cystic fibrosis, and immune deficiency)