Is pyogenic ethmoidal osteitis the cause of complicated rhinosinusitis with subperiosteal orbital abscess?

Multiple theories were described concerning the pathogenesis of orbital infection in rhinosinusitis, but no theory was proved. Understanding the cause of complication can allow its proper management. We speculate that subperiosteal orbital abscess (SPOA) secondary to rhinosinusitis is similar to subperiosteal abscess associated with osteomyelitis of bone all over the body. The objective was to evaluate bony changes of the ethmoidal sinuses in complicated rhinosinusitis patients with SPOA. This prospective controlled study was performed on eight patients undergoing endoscopic sinus surgery drainage for rhinosinusitis complicated with SPOA. Age, radiographic bony characteristics, and histopathological findings were all documented. Ethmoidal bone specimens were examined and assessed histopathologically. Purulence of SPOA was collected and sent for cultures. The authors evaluated normal ethmoidal bone specimens taken endoscopically from the medial wall of obstructing concha bullosa in ten control patients. The analysis revealed CT and histopathologic changes consistent with high grades of ethmoidal bone pyogenic osteitic changes. Coagulase-positive staphylococci were the predominant cultured bacteria (62.5%) in SPOA. These findings suggest that orbital subperiosteal abscess in rhinosinusitis patients is attributed to diffuse higher grades of ethmoidal sinus bony pyogenic osteitis. Staphylococcus aureus is the most commonly involved cultured bacteria. Bony osteitis in rhinosinusitis patients with SPOA is similar clinically and histopathologically in its character and behavior to osteomyelitis of bone all over the body with associated subperiosteal abscess.