Transient Bulging of the Fontanelle in Infants after a Febrile Illness without Central Nervous System Infection

Abstract

Increased intracranial pressure in infants with open cranial sutures can cause bulging of the anterior fontanelle. This condition is referred to as transient bulging of the fontanelle (TBF) if the bulging anterior fontanelle regresses spontaneously and no specific causes, such as central nervous system infection or a space-occupying lesion, can be identified. This is a different form of idiopathic intracranial hypertension that occurs during infancy. We encountered three infants with TBF who presented with irritability and a bulging anterior fontanelle after a febrile illness. There was no evidence of a central nervous system infection or a space-occupying lesion in any of the three infants. All three patients had normal cerebrospinal fluid (CSF) findings; negative blood, urine, and CSF cultures; and normal brain imaging studies. Associated infections were confirmed in two cases (rotaviral enteritis in one patient and exanthema subitum in the other). The bulging anterior fontanelle improved rapidly after lumbar puncture and resolved completely within 5 days. We report these three patients with TBF along with a review of the medical literature.