Orbital roof hyperostosis in a patient with history of sub-periosteal orbital abscess

We report a rare case of orbital wall change following the successful treatment of an orbital abscess in a 13-year-old boy. Initially presenting with left eye proptosis and eyelid puffiness, the patient was diagnosed with orbital cellulitis secondary to sinusitis and treated with intravenous antibiotics and surgical drainage. Although the infection resolved completely, six months later, the patient developed persistent upper eyelid swelling, ptosis, and mild proptosis. Imaging revealed significant thickening of the left orbital roof without active inflammation or lesions. Surgical exploration and histopathological analysis confirmed reactive hyperostosis of the orbital roof, likely due to periosteal elevation during abscess drainage. Unlike chronic rhinosinusitis (CRS) or orbital exenteration, where prolonged inflammation drives bone remodeling, no evidence of significant inflammation was observed in this case. Instead, the disruption of normal periosteal regulation may have triggered localized neo-osteogenesis. This case highlights an unusual occurrence for post-infectious orbital hyperostosis and emphasizes the importance of considering periosteal changes as a potential cause of late complications following orbital surgery or infection.