A 17-year-old girl who had right lower abdominal pain with multiple swelling of lymph nodes in the ileocecal region and she was admitted to a neighboring hospital. Since there was no improvement of condition with antibiotic resistance, we were consulted. Lymph node biopsy under laparoscopy demonstrated nonspecific findings. She then developed erythema nodosum, suggesting the presence of autoimmune etiology. Treatment with systemic corticosteroid resulted in symptomatic improvement. Mesenteric lymphadenitis like this case is rare.