context: Mesenteric lymphadenitis is an inflammation of lymph nodes. The lymph nodes that become inflamed are in a membrane that attaches the intestine to the abdominal wall. These lymph nodes are among the hundreds that help your body fight disease. They trap and destroy microscopic "invaders" like viruses or bacteria. Mesenteric lymphadenitis often causes abdominal pain. It is most common in children and teens. Sometimes doctors can't tell the cause of mesenteric lymphadenitis. But the most common cause is infection. Inflammatory conditions may also be linked with mesenteric lymphadenitis. Much less often, inflamed mesenteric lymph nodes result from cancer, including: Lymphoma Breast cancer Lung cancer Pancreatic cancer Gastrointestinal cancer Infections that cause mesenteric lymphadenitis may be located in one place (local) or throughout the body (systemic). The infections may be caused by: Viruses Bacteria Parasites Common infections that cause mesenteric lymphadenitis include: Gastroenteritis. This may result from viral infections such as rotavirus or norovirus. It may also result from bacterial infections such as salmonella, staphylococcus, or streptococcus. Gastroenteritis is often misnamed stomach flu. Yersinia enterocolitica. This is the most common cause of mesenteric lymphadenitis in children. This bacterium can cause gastroenteritis and other problems. It may resemble Crohn's disease or acute appendicitis. Other infections that cause mesenteric lymphadenitis include: Direct or indirect infections related to HIV. This is the virus that can lead to AIDS. Tuberculosis. This is a bacterial infection that usually attacks the lungs. But it can also attack other parts of the body. Acute terminal ileitis. This is an inflammation of the end of the small intestine. It may be due to a bacterium or Crohn's disease. Inflammatory conditions commonly linked to mesenteric lymphadenitis are: Appendicitis, inflammation of the appendix Inflammatory bowel diseases such as Crohn's disease or ulcerative colitis Connective tissue diseases such as lupus, sclerosis, or rheumatoid arthritis Diverticulitis, inflammation of the lining of the large intestine Pancreatitis, inflammation of the pancreas With mesenteric lymphadenitis, an upper respiratory tract infection may occur right before any other symptoms appear. This may cause symptoms such as a sore throat. Common symptoms of mesenteric lymphadenitis are: Tenderness or pain, often in the center or lower right side of the abdomen High fever Mesenteric lymphadenitis often causes symptoms in the lower right abdomen. So people often mistake it for appendicitis. You may have other signs and symptoms as well. This depends upon the cause of the inflammation. Signs and symptoms include: Feeling ill Loss of appetite Fatigue or lack of energy Raised white blood cell count Nausea, vomiting, or diarrhea Call your doctor right away if you or your child has severe or sudden abdominal pain. Also call if it occurs along with other symptoms such as those listed above. Describe to your doctor the severity and location of the pain, as well as what makes it worse. Be prepared to discuss any other symptoms you or your child has had. Sometimes mesenteric lymphadenitis causes no symptoms. The doctor may simply spot it while doing imaging tests for some other problem. Sometimes symptoms of mesenteric lymphadenitis may lead you to go to see a doctor. The doctor will ask about these symptoms and take a thorough medical history. He or she may also do some tests. Blood tests may help spot an infection. Urine tests may help rule out a urinary tract infection. An abdominal ultrasound or CT scan can help rule out other causes of symptoms. Many conditions are linked to mesenteric lymphadenitis -- some serious, others not. So you can see why a diagnosis is so important. Mesenteric lymphadenitis often gets better without treatment. Still, you may need medicine to reduce a fever or control pain. Rest, fluids, and warm heat applied to the abdomen may also help relieve symptoms. You may need treatment for the cause of the inflammation. Antibiotics can prevent complications from a severe bacterial infection (septicemia), which can cause death.