Acute pancreatitis due to influenza virus a with secondary appendicitis: the role of transabdominal ultrasound in the pediatric patient

A 6-year-old female patient presented to the pediatric Emergency Deparment complaining of abdominal pain with bilious vomits and fever within the last 2 days, in the setting of flu-like sypmptoms that had started five days earlier. Blood tests showed increased amylase and lipase levels (1752 and 2624 U/L, respectively) and an abdominal ultrasound showed signs of acute pancreatitis (Fig. 1a-b). The patient was admitted to the pediatric ICU with analgesia and intravenous fluid therapy, and a nasopharyngeal aspirate resulted positive for Influenza Virus A (IVA). Hours later, the patient's pain worsened and CRP levels increased significantly, thus a new ultrasound exam was ordered, which showed signs of incipient acute appendicitis (Fig. 1c-d). Emergent laparoscopic appendectomy was performed. Following surgery, antibiotics and oseltamivir were initiated. In the following days, the patient's condition improved and she was discharged six days after surgery.

Acute Pancreatitis (AP) is the most frequent pancreatic disorder in children, Two of three criteria (clinical, analytical or imaging) must be present for its diagnosis. Transabdominal ultrasound is the imaging technique of choice when AP is suspected in the pediatric patient. The most common findings include pancreas size increase and decreased echogenicity, but these may be normal features in some infants. More specific findings include dilatation of the pancreatic duct, poorly defined pancreatic borders and peripancreatic fluid. Radiologists ned to acknowledge the normal variability of the pancreas. Furthermore, potential reactive entities in other organs (e.g. appendicitis) warrant careful attention during the exam. Although the link between IVA and AP has not been definitely establishe, it was the only putative agent in the case depicted. Therefore, IVA should be considered among the causes of AP in pediatric patient.

Transabdominal ultrasound is the technique of choice in the initial assessment of children with suspected AP. Radiologists need to recognize the normal variability of thepancreas to avoid diagnostic pitfalls. Reactive abdominal entities should be ruled out. As a final remark, IVA should be regarded as a causative agent of AP.

- Restrepo R, Hagerott HE, Kulkarni S, Yasrebi M, Lee EY. Acute Pancreatitis in Pediatric Patients: Demographics, Etiology, and Diagnostic Imaging. AJR. 2016, 206(3): 632-44. - Rodríguez-Schulz D, Martínez A, Guzmán MB, Robledo H, C