The update group made strong recommendations that clinicians (1) should distinguish presumed ABRS from acute rhinosinusitis (ARS) caused by viral upper respiratory infections and noninfectious conditions and (2) should confirm a clinical diagnosis of CRS with objective documentation of sinonasal inflammation, which may be accomplished using anterior rhinoscopy, nasal endoscopy, or computed tomography. The update group made recommendations that clinicians (1) should either offer watchful waiting (without antibiotics) or prescribe initial antibiotic therapy for adults with uncomplicated ABRS; (2) should prescribe amoxicillin with or without clavulanate as first-line therapy for 5 to 10 days (if a decision is made to treat ABRS with an antibiotic); (3) should reassess the patient to confirm ABRS, exclude other causes of illness, and detect complications if the patient worsens or fails to improve with the initial management option by 7 days after diagnosis or worsens during the initial management; (4) should distinguish CRS and recurrent ARS from isolated episodes of ABRS and other causes of sinonasal symptoms; (5) should assess the patient with CRS or recurrent ARS for multiple chronic conditions that would modify management, such as asthma, cystic fibrosis, immunocompromised state, and ciliary dyskinesia; (6) should confirm the presence or absence of nasal polyps in a patient with CRS; and (7) should recommend saline nasal irrigation, topical intranasal corticosteroids, or both for symptom relief of CRS. The update group stated as options that clinicians may (1) recommend analgesics, topical intranasal steroids, and/or nasal saline irrigation for symptomatic relief of viral rhinosinusitis; (2) recommend analgesics, topical intranasal steroids, and/or nasal saline irrigation) for symptomatic relief of ABRS; and (3) obtain testing for allergy and immune function in evaluating a patient with CRS or recurrent ARS. The update group made recommendations that clinicians (1) should not obtain radiographic imaging for patients who meet diagnostic criteria for ARS, unless a complication or alternative diagnosis is suspected, and (2) should not prescribe topical or systemic antifungal therapy for patients with CRS.

Background:The body of knowledge regarding rhinosinusitis (RS) continues to expand, with rapid growth in number of publications, yet substantial variability in the quality of those presentations. In an effort to both consolidate and critically appraise this information, rhinologic experts from around the world have produced the International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR:RS). Methods:Evidence-based reviews with recommendations (EBRRs) were developed for scores of topics, using previously reported methodology. Where existing evidence was insufficient for an EBRR, an evidence-based review (EBR) was produced. The sections were then synthesized and the entire manuscript was then reviewed by all authors for consensus. Results:The resulting ICAR:RS document addresses multiple topics in RS, including acute RS (ARS), chronic RS (CRS) with and without nasal polyps (CRSwNP and CRSsNP), recurrent acute RS (RARS), acute exacerbation of CRS (AE-CRS), and pediatric RS. Conclusion:As a critical review of the RS literature, ICAR:RS provides a thorough review of pathophysiology and evidence-based recommendations for medical and surgical treatment. It also demonstrates the significant gaps in our understanding of the pathophysiology and optimal management of RS. Too o en the foundation upon which these recommendations are based is comprised of lowerlevel evidence. It is our hope that this summary of the evidence in RS will point out where additional research efforts may be directed. C 2016 ARS-AAOA, LLC. Key Words:rhinosinusitis; chronic rhinosinusitis; acute rhinosinusitis; recurrent acute rhinosinusitis; evidence-based medicine; systematic review; endoscopic sinus surgery List of Abbreviations Used

Background:The body of knowledge regarding rhinosinusitis (RS) continues to expand, with rapid growth in number of publications yet substantial variability in the quality of those presentations. In an effort to both consolidate and critically appraise this information, rhinologic experts from around the world have produced the International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR:RS). This executive summary consolidates the findings of the ICAR:RS document.Methods: ICAR:RS presents over 140 topics in the forms of evidence-based reviews with recommendations (EBRRs) and evidence-based reviews (EBR). The structured recommendations of the EBRR sections are summarized in this executive summary.Results: This summary compiles the EBRRs regarding medical and surgical management of acute RS (ARS) and chronic RS with and without nasal polyps (CRSwNP and CRSsNP). Conclusion:This ICAR:RS Executive Summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS. C 2016 ARS-AAOA, LLC.

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

I. Executive Summary Background The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS.