Overview Pediatric acute mesenteric lymphadenitis is one of the common causes of abdominal pain in children, mostly seen in children under 7 years of age, and is mostly a viral infection. Prevalent in the winter and spring, often complicating the course of acute upper whistle infection, or secondary to inflammatory bowel disease. Etiology 1, the pathogenesis: generally considered to be related to Salmonella infection. The disease is mainly transmitted through the fecal-oral route, but also by contaminated meat, eggs and other food or water transmission to people; hospitals can be contaminated with clothing, medical utensils, staff hands, toys, common plumbing, door handles and other nosocomial cross-infection, and in serious cases even cause an epidemic of outbreaks in the ward. 2.Pathogenesis: Pediatric mesenteric lymph nodes are abundantly distributed along the mesenteric artery and its arterial arch. The end of the ileum and the ileocecal part in particular, the contents of the small intestine often stay at the end of the ileum due to the role of the ileocecal valve, so the intestinal bacteria and viral products are easily absorbed there. After upper whistle infection or intestinal infection, viruses, bacteria and their toxins reach the lymph nodes in this area along the blood circulation, causing mesenteric lymphadenitis. Viral infections present as hyperplasia, edema, and congestion of the mesenteric lymph nodes, but cultures are negative. Salmonella infection causes mesenteric lymphadenitis different from viral lymphadenitis, bacterial invasion of the lymph nodes mostly manifested as acute inflammatory reaction, hemorrhage and necrosis in the lymph nodes, and Salmonella can be isolated from the lymph nodes. Clinical manifestations: 1. General manifestations: sore throat, tiredness and discomfort, followed by fever, abdominal pain, vomiting, sometimes with diarrhea or constipation. Younger children who present with clinically similar symptoms to appendicitis, but in a milder form, without abdominal muscle tension, should consider acute mesenteric lymphadenitis, mostly complicated in upper whistle infections or intestinal infections. 2, abdominal pain: the earliest symptoms of the disease, can be in any part, but because the lesion mainly invades a group of lymph nodes in the terminal ileum, so the right lower abdomen is common, the nature of abdominal pain is not fixed, can be manifested as vague pain or spasmodic pain, in between the two pain children feel better. Abdominal pain is common in the right lower abdomen and is paroxysmal and spasmodic, while rebound pain and abdominal muscle tension are rare. The most sensitive site of tenderness may be different on each physical examination, and the site of pressure pain is near the midline or high, unlike in acute appendicitis, and the degree is milder than in acute appendicitis, with less rebound pain and abdominal muscle tension. 3. Lymph node enlargement: About 20% of children have enlarged lymph nodes in the neck. Occasionally, small nodule-like masses with pressure pain can be found in the right lower abdomen as enlarged mesenteric lymph nodes. Ultrasonography, abdominal ultrasound, and routine imaging may be performed. Diagnosis: The diagnosis can be made by combining clinical manifestations, medical history and relevant examinations. The following tests may be performed to clarify the diagnosis: 1. Blood count: The white blood cells may be normal or mildly increased after the onset of the disease. Pathological examination: Pathological manifestations include lymph node hyperplasia, edema and congestion, but culture is often negative. 3.Fecal examination: Both stool and urine routine are normal. 4.Ultrasound examination: The abdominal mesentery is thickened, and multiple enlarged mesenteric lymph nodes of different sizes are seen, mostly in the right lower abdomen, with smooth and intact appearance, clear corticomedullary demarcation, hypoechoic, uniform echogenicity, and a small amount of liquid dark area in the abdomen. Treatment: If the diagnosis has been confirmed, conservative treatment, generally by fasting, intravenous fluids and antibiotics for abdominal pain, can significantly improve, gradually recover, without surgery. The undetectable warming effect of pulsed ultrashort wave treatment can cause changes in physiopathological processes and produce non-thermal effects. Ultrashort wave can make blood vessels dilate, improve blood circulation and accelerate the removal of inflammatory products. Ultrashort wave can reduce the excitability of sensory nerves, increase the pain threshold and achieve analgesia. Animal experiments have found that ultrashort wave has the effect of promoting gastrointestinal secretion and gastrointestinal absorption, and under the effect of warmth, it also has the effect of relieving the spasm of gastrointestinal tract. Pulsed ultrashort wave therapy enhances immune function and increases the number of phagocytes. Ultrashort wave has a good effect on the inflammatory process and can promote the absorption of inflammation products. Fast effect, no toxic side effects, no pain, easy to accept by the children, worthy of clinical promotion.