Although pleural effusion is a recognised (if unusual) complication of pancreatitis in adults, it is very rare in children.

We present the case of a nine year-old male patient, previously well,who presented after a holiday in Thailand with chronic back pain. Initial investigations were clear but he was admitted two weeks later with a massive right sided pleural effusion requiring repeated draining. Investigation showed no evidence of infection or malignancy, but he had a serum amylase level of 2096 (normal <106) and a pleural level of 35,240. His blood film showed an eosinophilia up to 2.5 × 10⁹/L (normal <0.4). Pancreatic ultrasonography and a subsequent MRCP and ERCP revealed material in an ectatic pancreatic duct with a proximal stricture. We believe that he had pancreatic duct obstruction due to Ascaris Lumbricoides although this could not be confirmed. He clinically improved post endoscopic decompression of the pancreatic duct through a transpapillary stent.

Pancreatic and biliary obstruction from helminths is well recognised in adults, as are pleural effusions caused by pancreatitis although the combination does not appear to have been previously reported in children. The pancreatic duct is surprisingly close to the pleural cavity, and the fistula develops as a result of tracking. Measurement of pleural amylase should be considered in cases of pleural effusion without evidence of infective or malignant cause.