In acute pancreatitis, the overflowing pancreatic fluid contains a large amount of pancreatic enzymes that spread along the tissue interstices and seep into the subcutaneous area where they can dissolve the subcutaneous fat, causing the capillaries to rupture and bleed, and the skin around the umbilicus to appear cyanotic called Cullen’s sign. This petechiae is caused by blood or activated protease entering subcutaneously through the peritoneum, fascia, and muscles, and appears late and is characteristic of necrotizing pancreatitis. What are the tests for acute pancreatitis? 1, white blood cell count In mild pancreatitis, it may not be increased or mildly increased, but in severe cases and with infection, it is often significantly increased, and neutrophils are also increased. 2.Amylase measurement This is one of the important objective indicators for the diagnosis of acute pancreatitis, but it is not a specific diagnostic method. In the early stage of the disease, pancreatic vascular embolism and some hemorrhagic necrotizing pancreatitis, due to the serious destruction of pancreatic tissue, it may not be increased. Sometimes amylase can be increased in cases of shock, acute renal failure, pneumonia, mumps, ulcerative perforation, and intestinal and biliary tract infections. Therefore, when there is an increase in amylase, the diagnosis of acute pancreatitis can be made only after combining the medical history, symptoms and signs and excluding amylase increases not caused by pancreatic diseases. There is also a relationship between amylase elevation and the time of onset of pancreatitis. According to clinical observation, there can be the following manifestations: ① 24h after the onset of the disease, serum amylase reaches the highest peak, and 48h after the peak of urinary amylase; ② within a short period of time after the onset of the disease, urinary amylase reaches the highest peak, while serum amylase may not be increased or mildly increased; ③ serum amylase and urinary amylase increase at the same time, but later gradually return to normal; ④ amylase rise and fall curve is wavy or long-term increase, revealing complications have occurred. It is worth mentioning that the degree of amylase increase is not necessarily proportional to the severity of inflammation, such as in edematous pancreatitis, amylase can reach a higher degree, while in some necrotizing pancreatitis, amylase does not increase due to the massive destruction of pancreatic tissue. There is disagreement in the literature as to which is accurate: serum amylase or urinary amylase. Some people believe that the determination of serum amylase is accurate, while others believe that urinary amylase is accurate and that urine is easy to collect and can be repeatedly examined. Therefore, at present, the clinical determination of urinary amylase is more frequent. In severe pancreatitis, the carbon dioxide binding capacity decreases and the blood urea nitrogen increases, indicating that the kidneys have been damaged. When the pancreatic islets are damaged, there may be an increase in blood sugar, but it is mostly transient. In hemorrhagic pancreatitis, blood calcium is often reduced, and when it is below 7mg%, it often indicates a poor prognosis. 4, laparotomy For cases with abdominal exudate, laparotomy can help the diagnosis of the disease. The puncture fluid is mostly bloody, and if the amylase measurement is increased, the diagnosis of the disease can be confirmed. 5, amylase isoenzyme test There are two identified amylase isoenzymes, pancreatic isoenzyme and salivary isoenzyme (STI). In acute pancreatitis, pancreatic isoenzymes can be significantly increased. For those with high suspicion of pancreatitis and normal amylase, it is more valuable to determine whether the amylase in hyperamylasemia originates from the pancreas. Some people in China use electrophoresis methods, from the cathode to the anode end of the PIA shows P3, P2, P1, of which P3 is a sensitive and reliable indicator for the diagnosis of acute pancreatitis. 6, radioimmuno-pancreatic enzyme assay (RIA) Because amylase assay is not specific for the diagnosis of pancreatitis, with the progress of immunoassay technology, many scholars look for a more accurate diagnostic method, namely radioimmunoassay of pancreatic enzymes.