Bulging fontanelle


Neonatal suture anatomy.
  • Fontanelles are fibrous, membrane-covered gaps between cranial bones.
  • A newborn has six fontanelles: anterior, posterior, two mastoid, and two sphenoid.
    • Anterior and posterior are the most prominent
    • The posterior fontanelle usually closes by 1-2 months of age.
    • The anterior fontanelle usually closes between 7-19 months of age.
  • A bulging fontanelle represents increased intracranial pressure, which may be transient and either benign or malignant.
  • Meticulous history and physical is essential to guide management of these infants.

Clinical Features

  • Bulging fontanelle

Differential Diagnosis


  • Clinical diagnosis
  • Evaluate for underlying etiology
  • Standard approach:
    • Head CT
    • LP (if not contraindicated by CT findings) with opening and closing pressures