Mesenteric adenitis is a self-limiting inflammatory condition that affects the lymph nodes in the mesentery. It is often mistaken for appendicitis due to similar symptoms, such as diffuse abdominal pain, low-grade fever, and generalized abdominal tenderness.

While mesenteric adenitis can affect individuals of any age, it is more prevalent in children and adolescents. The condition typically follows an upper respiratory tract infection, suggesting a link with viral pathogens.

Aetiology

While the exact cause of mesenteric adenitis is unknown, it is commonly associated with viral or bacterial infections that trigger an immune response, leading to inflammation of the mesenteric lymph nodes. Here are some common pathogens known to be linked with the condition:

• Viruses: A significant proportion of cases occur following viral infections, especially of the upper respiratory tract. Epstein-Barr virus (EBV), responsible for causing infectious mononucleosis, is among the most common viral triggers. Other viral etiologies include adenoviruses and enteroviruses.
• Bacteria: Certain bacterial infections, particularly those caused by Yersinia and Campylobacter species, are known to be associated with mesenteric adenitis. Yersinia enterocolitica and Yersinia pseudotuberculosis are often implicated and are typically contracted through contaminated food or water. Campylobacter infections usually occur due to ingestion of undercooked poultry or unpasteurized milk.
• Other Causes: Rarely, other pathogens such as Mycobacterium, Salmonella, and Streptococcus have been linked to the condition.

It's important to note that mesenteric adenitis often occurs after the initial infection has resolved, indicating a reactive process rather than an ongoing infection of the mesenteric lymph nodes themselves. This condition is more commonly seen in children and adolescents, suggesting a possible link with the maturation of the immune system. Furthermore, certain individuals may have a genetic predisposition to developing mesenteric adenitis, although further research is needed to fully understand this association.

PC

• Diffuse abdominal pain, often mistaken for appendicitis
• Low-grade fever
• Generalized abdominal tenderness
• Pharyngitis or sore throat

In children, these symptoms are usually accompanied by good overall health and an unaltered appetite.

Investigations

• Full blood count: Typically normal, unlike the elevated white cell count seen in appendicitis.