Many children go to the hospital with abdominal pain and the ultrasound reveals enlarged mesenteric lymph nodes, and the doctor tells them that it is mesenteric lymphadenitis. What is mesenteric lymphadenitis? I would like to briefly introduce it here with my own clinical experience. Mesenteric lymphadenitis is mainly seen in children and adolescents, and is a common cause of acute abdominal pain in children. Etiology: Lymph nodes are the immune organs of the body and are located throughout the body. When bacteria or viruses invade the surrounding area, the lymph nodes play the role of “eliminating the enemy and defending the country”. At the cost of “killing a thousand enemies and damaging eight hundred”, the corresponding lymph nodes become enlarged. The exact cause of mesenteric lymphadenitis is not known. Most often, the lymph nodes are enlarged in the ileocecal region. Because of the large number of lymph nodes in this area, which is particularly abundant in children, it is thought that the acute inflammatory response of the lymph nodes is caused by the easy absorption of toxins and bacteria in this area due to inflammation of the intestine. It is also believed that patients have fever or upper respiratory tract infection at the beginning of the disease, due to bloodstream infection by streptococci. Clinical manifestations 1. History There is often a recent history of upper respiratory tract infection. 2.Symptoms The main manifestation is abdominal pain, mostly around the umbilicus, with relatively irregular location. The degree is mild and mostly tolerable. Between episodes of pain, patients may have no other discomfort, and some children may be accompanied by nausea, vomiting, diarrhea or constipation. The most important point is that many children have a fever at the beginning of the attack, with a temperature often exceeding 38-39°C. This is the most important point to distinguish from appendicitis. This is an important basis for the differential diagnosis with appendicitis. The disease can be recurrent, but is mostly self-limiting. 3.Signs Abdominal pressure pain, mostly from the lower right to the upper left in an oblique distribution, but the right lower abdomen is obvious; there can be different degrees of pressure pain in the right lower abdomen, and the location of pressure pain is not consistent in each examination, and there is rarely muscle tension and rebound pain. 4, blood routine: white blood cell count is generally normal or slightly increased, and the proportion of lymphocytes may increase. Differential diagnosis This disease is easily confused with acute appendicitis. A significant number of children with appendicitis admitted to our clinic each year have a history of multiple so-called “mesenteric lymphadenitis”, and the disease should be differentiated from abdominal tumors and allergic purpura. The treatment is mainly symptomatic, i.e., physical cooling or medication to reduce fever, antispasmodic and analgesic for abdominal pain, antibiotics or antiviral medication for anti-infection (combined with routine blood results), etc. Note: The above is a personal opinion, it is recommended to go to a regular hospital promptly regardless of the situation.