Staphylococcus aureus costal osteomyelitis with complicated by pleural effusion in a 7-month-old infant: A misleading clinical presentation.

Osteomyelitis is a rare infectious disease in children, predominantly affecting long bones; however, its clinical presentation can be ambiguous if the location is atypical. Costal osteomyelitis is very rare in children and can mimic other pathologies. We present a case of a seven-month-old infant diagnosed with costal osteomyelitis complicated by rupture of a subperiosteal abscess into the pleura. His clinical condition improved with conservative treatment, which included chest drain insertion and intravenous antibiotic therapy without the need for surgical debridement. Rib osteomyelitis represents a potentially severe condition. Early detection is imperative to prevent the necessity for invasive therapies and mitigate long-term complications.