Defining Central Compartment Atopic Disease: A Systematic Review

Central compartment atopic disease (CCAD) is a chronic rhinosinusitis (CRS) phenotype that is becoming increasingly recognized. It is characterized by inflammatory remodeling of the middle and superior turbinates, as well as the posterosuperior nasal septum. Published studies have employed various endoscopic, radiological, and allergy-based definitions, which makes it difficult to compare allergic, inflammatory, and treatment outcomes. The authors conducted a systematic review of primary human studies that reported diagnostic, clinical, radiological, inflammatory, olfactory or treatment data for CCAD. The authors searched MEDLINE/PubMed, Embase, Scopus, and Web of Science, and included 20 primary studies from the 327 records identified. The most consistently reported anatomical feature was inflammatory remodelling arising from central nasal structures on endoscopic examination. However, formal diagnostic accuracy evidence using an independent reference standard remains limited. Computed tomography was useful for defining the distribution of the condition, olfactory cleft involvement and secondary sinus obstruction, but did not consistently establish the origin of the tissue. Reported aeroallergen sensitization, asthma, and eosinophilic burden varied across populations and were influenced by differences in case definition and testing methodology. Patients with isolated centralcompartment- predominant CRS and those with diffuse chronic rhinosinusitis with nasal polyps and concomitant central involvement showed different postoperative outcomes and should be analyzed separately. There is limited therapeutic evidence: surgical outcomes are mainly derived from observational cohorts, allergen immunotherapy from a non-randomized cohort, and combined topical azelastine/fluticasone from 1 small randomized trial. Contemporary evidence favors an endoscopy-centered working framework for CCAD, although prospective diagnostic validation remains limited, and allergy should be characterized rather than assumed to be synonymous with the anatomical phenotype.