Pott's puffy tumor: a forgotten differential diagnosis of frontal swelling of the forehead.

A 14-year-old adolescent boy experienced a nonsevere infection of the upper respiratory tract. After 10 days, he developed headache, intermittent vomiting, and fever. A sudden prominent swelling of the forehead occurred, and his general condition deteriorated. Cranial computed tomography showed a subdural empyema and subperiosteal abscess owing to osteomyelitis of the frontal bone. Surgical drainage of the subdural empyema and the subperiosteal abscess was performed, and appropriate long-term antibiotic therapy was initiated. The swelling of the forehead caused by a subperiosteal abscess with osteomyelitis of the frontal bone after frontal sinusitis or trauma is known as Pott's puffy tumor. This case demonstrates that swelling of the forehead in the presence of upper respiratory tract infection should lead to prompt evaluation for complications.