Chronic extensive necrotizing abscess of the scalp.

Chronic subgaleal abscesses have been extremely rare since the advent of antimicrobial therapy. The majority of reported cases have occurred as acute infections following traumatic scalp lacerations or needle electrode insertion for fetal monitoring. The rich blood supply of the head makes widespread infection from a scalp surgical wound a very unlikely occurrence. Most acute infections of the scalp result in complete resolution with adequate early treatment. However, extensive purulent fibrosis of the scalp remains a potentially serious surgical complication. We report 2 cases of chronic necrotizing abscess of the scalp associated with a postsurgical scalp ulcer. The inflammatory process caused extensive necrotizing fibrosis (up to 2.5 cm thick) of the entire undersurface of the scalp and involved both the galea aponeurotica and the periosteum. We discuss the unique pathological features of this entity along with recommendations for its operative management and suggestions for flap design.