Osteitis in chronic rhinosinusitis: a histopathological study of human ethmoid bone remodeling in allergic versus non-allergic chronic rhinosinusitis

BackgroundChronic rhinosinusitis (CRS) is a disease characterized by inflammation of the mucosa lining the paranasal sinuses; however, recent evidence also indicates the involvement of the sinus bones in the inflammatory process. CRS is a disease with different phenotypes; nonetheless, the characterization of osteitis in the different CRS phenotypes is poorly characterized. Herein, we report on osteitis in two main phenotypes of CRS: a group allergic to aeroallergens who suffers from long-lasting upper airway allergy, and the CRS group with no upper airway allergy.Patients and methodology A total of 51 patients (23 females and 28 males, with a mean age of 39.03±13.4) who underwent surgery in our university hospital contributed to this study by providing bone samples from the ethmoid bone. They were divided into three groups: group I is patients who underwent septoplasty with or without partial inferior turbinectomy, and they acted as the control group; group II is patients who underwent operation for non-allergic CRS (NACRS); and group III is patients who underwent operation for allergic CRS (ACRS). Sections of the decalcified ethmoid bone were stained with hematoxylin and eosin for histological evaluation for osteitis (periosteal thickening and remodeling, osteoblastic and osteoclastic activity, and osteomyelitis and bone destruction) that was graded from 0 to IV, where grade 0 is normal histology and grade IV is frank osteomyelitis and bone destruction.ResultsDescriptive histology of the ethmoid bone analysis demonstrated osteitis of different grades in patients suffering from CRS with or without upper airway allergy. In the ACRS group, 80% demonstrated grade I osteitis, and 20% grade II. However, 11.11% of the NACRS group demonstrated normal bone histology, and 88.88% demonstrated osteitis: 33.33% demonstrated grade I, 50% grade II, and 5.5% grade III. The control group showed normal bone histology in 90.47% and grade I osteitis in 9.52%. The mucosal disease was higher in the grade of inflammation than the osteitis in both CRS groups (II and III). There was no correlation between the mucosal and bone grade of inflammation in both CRS groups.Conclusion Herein, we show evidence of osteitis in ACRS and confirm the presence of a higher grade osteitis in the NACRS patients. This sinus bone remodeling may contribute to the chronicity of the disease and carries special consideration in the treatment of CRS.