Sub-aponeurotic fluid collections in infancy

To describe the radiological features and natural history of sub-aponeurotic fluid collections presenting after the neonatal period.

All cases of sub-aponeurotic scalp fluid collection presenting to the radiology department between June 1996 and June 2000 were reviewed. Note was made of the birth history, the radiographic and ultrasound features and the natural history (including any treatment) of the collection.

Seven cases of sub-aponeurotic fluid collections were identified. There were six infants who presented 3.5-18 weeks (mean nine weeks) after delivery, four of whom had had ventouse-assisted delivery. The last case was in a seven-year-old child who presented one month after minor head trauma. Clinical examination revealed non-tender, soft, mobile and fluctuant scalp swellings in all patients. Ultrasound identified sonolucent fluid collections of between 5 and 24 mm depth in the sub-aponeurotic space. No skull fractures were identified. Six patients were treated conservatively and one had fluid aspirated and a compression bandage applied. All cases resolved 2-24 weeks after diagnosis and there were no long-term sequelae.

Sub-aponeurotic scalp collections presenting after the neonatal period are usually associated with ventouse-assisted delivery ultrasound is useful for diagnosis. The condition is benign and resolution occurs with conservative treatment.