Scalp abscess--a cautionary tale.

Transcranial extension of frontal sinus infection is a rare, but not eradicated entity. We present a 21-year-old male, in whom a persistent scalp abscess heralded the discovery of skull vault osteomyelitis and extradural abscesses secondary to frontal sinusitis. Patients with prolonged or unusual symptoms with a history of sinusitis or trauma warrant further investigation as they may have developed serious intracranial complications. Urgent management, both surgical and antimicrobial, is indicated in such scenarios.