Subaponeurotic or subgaleal fluid collections in infancy: an unusual but distinct cause of scalp swelling in infancy

Subaponeurotic or subgaleal fluid collection is a rare but important cause of scalp swelling in young infants. Fluid in the subaponeurotic or subgaleal space presents as soft, ill-defined, fluctuant, highly mobile scalp swelling and is not limited by suture lines, which makes it clinically very distinct from other scalp swellings. However, the aetiology of such swelling still remains uncertain but may be related to traumatic labour that manifests after the first few weeks of life. There is no indication for imaging if the condition is diagnosed clinically with confidence. The late subaponeurotic or subgaleal fluid collection resolves spontaneously without any intervention, hence conservative management is the treatment of choice.