Mesenteric adenitis is a condition that more often affects children and teenagers. It causes inflammation and swelling in the lymph nodes inside the abdomen. Lymph nodes are small, bean-shaped organs that contain white blood cells called lymphocytes. They are part of your body’s lymphatic system. Lymph nodes play an important role in the immune system. They filter out bacteria and other germs from the lymph fluid so your body can remove these harmful substances.

Mesenteric adenitis affects lymph nodes in tissue called mesentery. This tissue connects the intestines to the abdominal wall. Another name for mesenteric adenitis is mesenteric lymphadenitis.

Symptoms of mesenteric adenitis can include:

  • pain in the lower right part of the abdomen, or in other parts of the belly
  • fever
  • nausea and vomiting
  • diarrhea
  • general sick feeling, called malaise
  • weight loss

These symptoms may appear after your child has a cold or other respiratory infection.

Mesenteric adenitis has similar symptoms to appendicitis. Appendicitis is inflammation in the appendix. The appendix is the small pouch off the cecum of the colon, in the lower right side of the abdomen. Sometimes the two conditions can be hard to tell apart.

In mesenteric adenitis, the pain may also be in other parts of your child’s belly. The symptoms could start after a cold or other viral infection. Appendicitis typically comes on suddenly, without any other illness before it.

The main difference is that mesenteric adenitis is less serious than appendicitis. It usually gets better on its own. Appendicitis usually requires surgery called an appendectomy to remove the appendix.

Learn more: How to recognize and react to appendicitis in children »

A bout of the stomach flu or another infection in your abdomen can cause inflamed and swollen lymph nodes in and around the mesentery. Again, this is the tissue that attaches your intestines to the abdominal wall.

When you get an infection, bacteria, viruses, or other germs filter through your lymph nodes and cause them to become inflamed and swell up. Lymph nodes are part of the body’s immune response. They capture bacteria, viruses, and other germs, and they clear them out of your system to prevent you from getting sick. That’s why you’ll sometimes feel enlarged, swollen lymph nodes in your neck or other places when you’re sick.

Bacteria, viruses, and parasites can cause this condition. Below are some of the most common.

Bartonella henselae (cat scratch disease)Giardia lambliaacute HIV infection
Beta-hemolytic streptococciadenoviruses
Escherichia coli (E. coli)co sackie viruses
Mycobacterium tuberculosisEpstein-Barr virus
Staphylococcus speciesrubeola virus (measles)
Streptococcus viridans
Yersinia enterocolitica

Mesenteric adenitis is often seen after viral gastroenteritis, also called the stomach flu. Your child might also get this condition after a respiratory infection. Some kids get mesenteric adenitis from eating undercooked pork that’s been contaminated with the bacterium Yersinia enterocolitica.

You can get mesenteric adenitis at any age, but it’s most common in children.

Children are more likely to get mesenteric adenitis after:

  • a stomach virus
  • a cold virus or other respiratory infection
  • eating pork contaminated with Y. enterocolitica

Kids often get stomachaches. Usually, they’re not serious.

Symptoms of mesenteric adenitis include:

  • belly pain that comes on suddenly and is severe
  • belly pain that happens with fever, diarrhea, vomiting, or weight loss
  • symptoms that don’t improve, or get worse

Your child’s doctor will ask about your child’s symptoms. They’ll also ask whether your child recently had a cold, stomach bug, or other infection. The doctor may feel your child’s belly to check for any tenderness or swelling, and to feel if any lymph nodes are enlarged.

The doctor may take a blood sample to check for infection. Your child might also need an imaging test to look for enlarged lymph nodes in the abdomen. Your doctor can use the following tests to tell the difference between mesenteric adenitis and appendicitis:

  • CT (computed tomography) scan is an imaging test that uses a powerful X-ray to take pictures inside the abdomen
  • ultrasound in an imaging test that uses ultrasonic sound waves to show a picture of the inside of the abdomen

Mesenteric adenitis usually starts to get better in a few days without treatment. Children who have a bacterial infection may need to take antibiotic therapy.

To keep your child comfortable, you can give over-the-counter (OTC) pain relievers like ibuprofen (Advil, Motrin) or acetaminophen (Tylenol). Don’t give aspirin to kids with flu-like symptoms. Aspirin has been linked to a rare, but serious condition called Reye syndrome in children and teens.

Mesenteric adenitis is usually not serious. However, sometimes it can cause complications that include:

  • abscess, which is a pocket of pus in the abdomen
  • dehydration if your child has severe diarrhea or vomiting
  • joint pain called arthralgia
  • peritonitis, a rare condition that causes inflammation of the membrane that surrounds the outside of the organs in the abdomen
  • sepsis, which is a result of an infection causing systemic inflammatory response syndrome

Mesenteric adenitis usually isn’t serious. It should improve on its own within a few days.

People who’ve had mesenteric adenitis have a lower risk for ulcerative colitis, a form of inflammatory bowel disease. Doctors don’t know the exact reason for this reduced risk.