Acute and Chronic Rhinosinusitis

Rhinosinusitis is symptomatic inflammation of the nose and the paranasal sinuses. It is classified by duration: acute rhinosinusitis lasts less than twelve weeks and resolves completely, while chronic rhinosinusitis persists for twelve weeks or longer. Both are defined by a combination of cardinal symptoms together with objective signs of mucosal inflammation on endoscopy or imaging.

Definition

Rhinosinusitis is inflammation of the nose and paranasal sinuses characterised by two or more symptoms, one of which is nasal blockage or nasal discharge, plus facial pain/pressure or reduction in smell, accompanied by endoscopic or CT signs of disease; it is termed acute when it resolves within twelve weeks and chronic when symptoms persist for twelve weeks or more.

Scope

The entry covers how rhinosinusitis is defined and split into acute and chronic forms, the symptom criteria used in current guidelines, the chronic phenotypes (with and without nasal polyps), and the inflammatory mechanisms and evidence framework behind them. It is reference-educational and does not provide individualised diagnostic or treatment recommendations.

Core questions

• How do current position papers define rhinosinusitis and separate acute from chronic disease?
• What distinguishes chronic rhinosinusitis with nasal polyps from chronic rhinosinusitis without polyps?
• What roles do infection and type 2 inflammation play in each form?
• What does the controlled-trial and systematic-review evidence support?

Key concepts

• Acute rhinosinusitis (ARS)
• Chronic rhinosinusitis (CRS)
• CRS with nasal polyps (CRSwNP)
• CRS without nasal polyps (CRSsNP)
• Cardinal symptom criteria
• Type 2 inflammation and endotypes
• Ostiomeatal complex obstruction
• Endoscopy and CT confirmation

Mechanisms

Acute rhinosinusitis usually begins as a viral upper respiratory infection that causes mucosal oedema, impairs sinus drainage through the ostiomeatal complex, and occasionally progresses to bacterial infection. Chronic rhinosinusitis is a persistent inflammatory state of the sinonasal mucosa; current frameworks describe it less by anatomy than by underlying immune endotype, with type 2 (eosinophilic) inflammation predominating in much of chronic rhinosinusitis with nasal polyps and a more variable picture in disease without polyps. EPOS 2020 and ICAR-RS 2021 formalise these phenotype and endotype distinctions, and the cardinal-symptom definition links the clinical syndrome to objective endoscopic or CT findings.

Clinical relevance

Rhinosinusitis is one of the most common conditions managed in primary care and otolaryngology and a frequent reason for antibiotic prescribing and sinus surgery. Knowing how the acute and chronic forms are defined and phenotyped supports appraisal of the evidence and guidelines; this entry describes the disease and its classification and is not a basis for individual diagnosis or therapy.

Epidemiology

Acute rhinosinusitis is extremely common, largely viral, and mostly self-limited, while chronic rhinosinusitis affects on the order of one in ten adults in population-based surveys in Europe and the United States, where symptom-based and physician-confirmed estimates differ. Chronic disease is a leading driver of impaired quality of life and health-care use in rhinology.

Evidence & guidelines

The European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2020), the International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS 2021), and the AAO-HNS Clinical Practice Guideline on Adult Sinusitis (2015) define the entities and grade interventions; Cochrane systematic reviews, such as Chong and colleagues on intranasal corticosteroids, summarise the trial evidence for chronic disease.

History

Sinus disease has been recognised since antiquity, but its modern definition was reshaped by nasal endoscopy and functional endoscopic sinus surgery in the 1980s, which allowed direct assessment of the ostiomeatal complex. The European Position Papers from 2005 onward standardised the symptom-based definition and the acute/chronic split, and the 2020 edition emphasised endotyping by inflammatory pattern.

Debates

Should chronic rhinosinusitis be classified by polyp phenotype or by inflammatory endotype?

Traditional classification separates disease with and without nasal polyps, but a growing body of work argues that the underlying immune endotype, especially type 2 inflammation, better predicts disease behaviour and response to targeted therapy; current position papers incorporate both views.

Key figures

• Wytske Fokkens
• Valerie Lund
• Claire Hopkins
• Richard Rosenfeld
• Richard Orlandi

Seminal works

• fokkens-2020-epos
• rosenfeld-2015-sinusitis
• orlandi-2021-icar

Frequently asked questions

What separates acute from chronic rhinosinusitis?

Duration: by convention acute rhinosinusitis resolves within twelve weeks, whereas chronic rhinosinusitis is defined by symptoms persisting for twelve weeks or longer together with objective signs of inflammation.

Is chronic rhinosinusitis the same as a sinus infection?

No. Acute rhinosinusitis is often an infection, usually viral, whereas chronic rhinosinusitis is primarily a persistent inflammatory disorder of the sinonasal mucosa in which infection is only one possible contributor.