Pancreatitis is diagnosed by clinical presentation, laboratory, and imaging tests. Children should meet at least two of the following three parameters to qualify as having acute pancreatitis: abdominal pain, elevated amylase/lipase usually greater than three times the upper limit of normal, or confirmatory findings on cross-sectional abdominal imaging such as ultrasound, computed tomography (CT) scan, or magnetic resonance imaging (MRI).2,3
In pediatric studies of acute pancreatitis, 80% to 95% of patients present with abdominal pain.2–5 The most common location of pain is the epigastric region (62%–89% of cases). However, occasionally pain can be diffuse, located in the lower abdomen and sometimes radiates to the back. In young children, irritability and fever are often nonspecific presenting complaints.16,17 The second most common symptom is nausea or vomiting, and is reported in 40% to 80% of patients.2 Other symptoms can include fever and jaundice.
Physical examination can be quite variable.3 The child is often still but becomes uncomfortable with movement. Tachycardia, fever, diffuse abdominal tenderness, quiet bowel sounds can be present. Other findings include dyspnea and epigastric mass (pseudocyst formation). Rarely, there may be signs of hemorrhagic pancreatitis with bluish flanks (Grey-Turner sign) or a bluish area surrounding the umbilicus (Cullen sign).5
Elevations in serum amylase and lipase are the most common biochemical determinants of pancreatitis. In pediatric studies, the sensitivity of the amylase test in diagnosing pancreatitis has ranged from 50% to 90%.2,5 In particular, serum amylase elevations can arise from nonpancreatic sources such as the salivary gland and intestine or result from reduced renal clearance. In addition, newborn levels of total amylase and pancreatic isoamylase are very low. Total amylase levels reach normal adult values by 8 to 18 months of age and pancreatic isoamylase levels reach adult values by 10 to 15 years of age.3
Lipase levels are also low at birth and slowly increase by 12 months of life.3 Lipase levels can be increased in intestinal diseases as well. In pancreatitis, lipase remains elevated longer than amylase levels. Neither amylase nor lipase correlates with pancreatitis severity. Therefore, it is recommended that both amylase and lipase be obtained in children suspected of pancreatitis. The elevation of amylase and lipase in children has a sensitivity of 94%.18 Serum cationic trypsinogen, and trypsinogen activation peptide are currently being investigated as possible marker of pancreatitis.2,19
White blood cell count (WBC) and hematocrit are often elevated due to hemoconcentration and volume depletion. Hypocalcemia and hyperglycemia can be seen in acute pancreatitis.
Imaging modalities can confirm the diagnosis of pancreatitis, help to identify the cause, and assess for complications. Ultrasound is often recommended as the initial imaging test. An enlarged, edematous pancreas or decreased pancreatic echogenicity suggests pancreatitis but the sensitivity is only 33% to 67%.2,5,20 However, it can also evaluate for possible gallstones, fluid collections, abnormalities in pancreaticobiliary drainage system and can look for other causes of an acute abdomen (e.g., appendicitis, intussusception, volvulus).20
CT with contrast is helpful in evaluating the severity of pancreatitis but due to radiation exposure, it is only recommended for complicated cases or if the diagnosis is unclear.21,22 MRI is noninvasive, radiation free but the data is still limited in children with pancreatitis.23 Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS) are becoming more utilized and experience with these modalities is increasing.24,25
In adults, clinical scales such as Ranson criteria and Glasgow score are used to measure the severity and prognosis of acute pancreatitis after 48 hours. Unfortunately, these have shown to have low sensitivity and negative predictive value in children.26 A PAPS scoring system was created to predict severity and major complications with acute pancreatitis but this also showed limited ability to predict severity in children.26,27 However, statistical regression analysis suggests that admission WBC count, calcium levels, and BUN levels are important factors in evaluating the severity of pancreatitis and should be considered for future scoring systems.26