The anterior fontanel is one of evolution's gifts to physicians who care for children. Pathological prominence or "bulging of the fontanel" is supposed to be a sine qua non of acute bacterial meningitis in infants. Review of multiple early and current texts in pediatrics and infectious diseases failed to disclose a satisfactory explanation for the pathophysiology of the bulging fontanel in meningitis. A computed tomographic head scan of an infant who had this sign early in the course of acute bacterial meningitis helped elucidate its pathogenesis.
Steven M. Rothman, Benjamin C. P. Lee. What Bulges Under a Bulging Fontanel?. Arch Pediatr Adolesc Med. 1998;152(1):100–101. doi: