If a 4-month-old infant has an anterior fontanel that has fused, what should be the best plan?

The most appropriate plan when a 4-month-old infant has a fused anterior fontanel is to refer to a pediatric neurosurgeon. Normally, the anterior fontanel remains open until about 12 to 18 months of age. If it has fused earlier than expected, it can indicate a condition known as craniosynostosis, where one or more of the cranial sutures close prematurely. This can lead to various complications, including raised intracranial pressure and abnormal head shape, which may require surgical intervention.

Referring to a pediatric neurosurgeon allows for a proper evaluation and management of the infant's condition. The neurosurgeon can determine if there is indeed a pathological fusion of the sutures and recommend the necessary interventions, whether it be monitoring or surgical procedures. Early referral is important since timely intervention can prevent possible developmental delays and other complications associated with restricted brain growth.