Fontanelles are fibrous membrane-covered gaps between cranial bones. A newborn has six fontanelles: anterior, posterior, two mastoid, and two sphenoid. The most prominent are the anterior and posterior fontanelles
A bulging fontanelle represents increased intracranial pressure, which may be transient, benign, or malignant. The most commonly considered etiologies include Meningitis, space-occupying lesion, cerebral edema, and hemorrhage (spontaneous, non-accidental, or traumatic). A meticulous history and physical is essential to guide management of these infants.
- The posterior fontanelle usually closes by 1-2 months of age.
- The anterior fontanelle usually closes between 7-19 months of age.
- Congestive Heart Failure
- Space-occupying lesions
- Thyroid disorders
- Intracranial Hemorrhage
- Parathyroid disorders
- Brain Abscess
- Diabetic Ketoacidosis
- Hypervitaminosis A
- Lead encephalopathy
- Inborn errors of metabolism
- Roseola Infantum
- Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)
- Dural sinus thrombosis
- Viral syndromes
- Head CT followed by Lumbar Puncture if not contraindicated by CT findings
- Record opening and closing pressures in children is warranted
for a well appearing, asymptomatic, afebrile child with bulging fontanelle, an observation period may be appropriate. In these stable children, if a subacute condition such as an asymptomatic space-occupying lesion is likely, he may benefit from admission and MRI
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