Acute nonspecific, or primary, mesenteric lymphadenitis is a self-limiting inflammatory condition affecting the mesenteric lymph nodes, whose presentation mimics appendicitis or intussusception. It typically occurs in children, adolescents, and young adults. White blood count and C-reactive protein are of limited usefulness in distinguishing between patients with and without mesenteric lymphadenitis. Ultrasonography, the mainstay of diagnosis, discloses 3 or more mesenteric lymph nodes with a short-axis diameter of 8 mm or more without any identifiable underlying inflammatory process. Once the diagnosis is established, supportive care including hydration and pain medication is advised. Furthermore, it is crucial to reassure patients and families by explaining the condition and stating that affected patients recover completely without residuals within 2–4 weeks.

In patients affected with acute nonspecific mesenteric lymphadenitis, it is advantageous to think of the time span for recovery in terms of ≥ 4 weeks. What is Known: • Mesenteric adenitis is a self-limiting inflammatory condition with well-characterized clinical presentation and imaging features. • A total duration of symptoms of ≤ 4 weeks is usually hypothesized. What is New: • Symptoms persist for 3 to 10 weeks in half of the patients. • At presentation, clinical and laboratory characteristics are similar in children with symptoms persisting for 2 weeks or less and in those with 45 symptoms persisting for 3-10 weeks.