Fifteen-minute consultation on the infant with a large head.

An infant with a large head (2.5 SDs above normal for weight and gender or above 99.6th centile for age) is a common clinical presentation. Usually, it is due to benign isolated macrocephaly or familial macrocephaly (FM) where some close family members are similarly affected(1); neither condition requires any further intervention. However, there are a few important underlying causes the clinician needs to actively consider and investigate when indicated before reassuring parents. These considerations include whether there is any associated developmental disorder or suggestion of a syndromic association or evidence of raised intracranial pressure (ICP).