Description

Mesenteric adenitis is defined as inflammation of the mesenteric lymph nodes. The inflamed nodes are usually clustered in the right lower quadrant (RLQ) small bowel mesentery or are located ventral to the psoas muscle.

Epidemiology

• Age related, most common in patients <15 years of age
• Affects males and females equally
• History of recent sore throat or upper respiratory tract infection found in 20–30% of subjects
• Most common cause of acute abdominal pain in young adults and children
• Self-limiting condition
• Most common cause of inflammatory adenopathy (more common than tuberculosis)
• Mesenteric adenitis in childhood is related to a decreased risk of ulcerative colitis in adulthood.

Pathophysiology

• Lymph nodes involved are those draining the ileocecal area. Lymph nodes absorb toxic products or bacterial products secondary to stasis.
• Nodes are enlarged up to 10 mm; discrete, soft, and pink; and with time, become firm. Calcification and suppuration are rare.
• Cultures of the nodes are negative.
• Reactive hyperplasia: Adenitis results from a reaction to some material absorbed from the small intestine, reaching the intestine from the blood or lymphatic system.
• Hypersensitivity reaction to a foreign protein

Etiology

• Viral
  • Adenovirus
  • Echovirus 1 and 14
  • Coxsackieviruses
  • Epstein-Barr virus (EBV)
  • Cytomegalovirus (CMV)
  • HIV
• Bacterial
  • Tuberculosis
  • Streptococcus species
  • Staphylococcus species
  • Escherichia coli
  • Yersinia enterocolitica
  • Bartonella henselae (cat-scratch disease)