Classifying Chronic Rhinosinusitis: What EPOS 2020 Changes for Your Practice

Scott Fortune, MD, FAAOA; Meha Fox, MD, FAAOA; Peter Filip, MD, FAAOA

If you’ve trained in the last decade, you probably learned to classify chronic rhinosinusitis as one of two things: CRS with nasal polyps or CRS without nasal polyps. That’s CRSwNP and CRSsNP. Simple. Clean. Easy to document.

But here’s the problem — that binary has been quietly failing us for years. It doesn’t tell us why a patient has polyps. It doesn’t predict who will respond to biologics. And it doesn’t explain why two patients with identical CT scans can have completely different disease trajectories.

EPOS 2020 — the European Position Paper on Rhinosinusitis and Nasal Polyps — rewired how we should think about this disease. In this podcast we’re going to walk through their classification framework, explain the biological logic behind it, and talk about what this means for how you actually manage patients in your clinic.

Watch this podcast to learn more.

Key References:

Fokkens WJ, et al. EPOS 2020: European Position Paper on Rhinosinusitis and Nasal

Polyps 2020. Rhinology. 2020;58(Suppl S29):1-464.

Additional Suggested Reading:

Laidlaw TM, Mullol J, et al. Biologics for CRSwNP and AERD. J Allergy Clin Immunol

Pract. 2021.

Soler ZM, et al. Eosinophilic CRS across the United States. Am J Rhinol Allergy. 2022.

Stevens WW, et al. Central Compartment Atopic Disease. Am J Rhinol Allergy. 2015.

Mullol J, Han JK, Laidlaw TM, Hopkins C, Peters AT, Pfaar O, Desrosiers M, Lee SE, Lane AP, Chen C, Chon Y, Ponnarambil SS, Foster A, Lindsley AW, Ambrose CS. Early and Sustained Improvements in Sense of Smell With Tezepelumab Treatment in Patients With Chronic Rhinosinusitis With Nasal Polyps (WAYPOINT). Int Forum Allergy Rhinol. 2026 May;16(5):484-494. doi: 10.1002/alr.70090. Epub 2026 Jan 6. PMID: 41493192; PMCID: PMC13147228.

Key Terms Defined in Episode:

CRS — Chronic Rhinosinusitis

CRSwNP—Chronic Rhinosinusitis with Nasal Polyps

CRSsNP—Chronic Rhinosinusitis without Nasal Polyps

EPOS — European Position Paper on Rhinosinusitis and Nasal Polyps

AFRS — Allergic Fungal Rhinosinusitis

CCAD — Central Compartment Atopic Disease

eCRS — Eosinophilic CRS

Type 2 inflammation — Th2/ILC2-mediated, IL-4/IL-5/IL-13 cytokine signature,

eosinophil-dominant

Non-eCRS — Non-eosinophilic CRS, includes neutrophilic and other endotypes

Dupilumab — IL-4Rα antagonist (Dupixent); FDA approved for CRSwNP

Mepolizumab / Benralizumab — Anti-IL-5 biologics