Fontanelle Facts

A bulging fontanelle in infants requires immediate clinical evaluation to rule out serious intracranial pathology. Proper assessment begins by examining the child in an upright position to ensure the finding is not gravity-dependent. While fontanelles serve critical roles in cranial development and birth, a persistent bulge acts as a high-risk indicator for hemorrhage, infection, or tumors. Emergency management typically involves a computed tomography (CT) scan to assess for structural abnormalities or increased pressure, followed by a lumbar puncture to exclude meningitis. Although rare, benign causes such as post-vaccination reactions or viral illnesses can also present with fontanelle changes. Clinicians must maintain a low threshold for investigation, as the default approach remains a comprehensive workup to ensure patient safety, even when the infant appears otherwise well.