Delayed Subaponeurotic Fluid Collection in Infancy: A Case Report and Literature Review.

Delayed subaponeurotic fluid collection (DSFC) is a rare, benign cause of scalp swelling in infants, typically arising weeks after birth and often linked to instrumental deliveries. We report a case of a healthy infant who presented at 10 weeks with asymptomatic, unilateral parieto-occipital swelling that resolved spontaneously within four weeks. Notably, the infant experienced a bilateral biparietal recurrence at six months, a less commonly reported manifestation. Imaging confirmed subaponeurotic fluid without underlying abnormalities. This case highlights the self-limiting nature of DSFC, even when recurrent, and underscores the importance of distinguishing it from serious conditions such as subgaleal haemorrhage, cephalohematoma, or non-accidental injury. MRI was instrumental in ruling out persistent cerebrospinal fluid leakage. Awareness of DSFC's variable presentation can prevent unnecessary interventions and parental distress. Clinicians should adopt a conservative approach while ensuring appropriate imaging in atypical or persistent cases.