Cephalhematomas revisited. When should a diagnostic tap be performed?

The purpose of this article is to review the most appropriate method for investigating cephalhematomas for possible infection and to clarify the indications for diagnostic aspiration. MEDLINE searches were conducted for the period from 1972 to 1993, and all English-language reports were obtained. A summary of the findings from the reports identified was supplemented by a patient report. Eleven articles reporting 13 infected cephalhematomas were identified in the literature from 1972 to 1993. Escherichia coli was isolated from approximately 50% of the cephalhematomas that were aspirated. Most patients presented with obvious clinical signs of scalp infection, sepsis, meningitis, and/or osteomyelitis. Plain radiographs, bone scans, and enhanced CT scans were limited in their ability to determine if a cephalhematoma was infected unless associated osteomyelitis existed. Aspiration is the diagnostic procedure of choice for cephalhematomas suspected of being infected, as indicated by an increase in size, development of erythema, development of fluctuance, relapse of systemic infection, or a delay in the resolution of clinical symptoms of infection.