Authors: Jesús Miguel Figueroa Zaldívar , Marco Antonio Rodríguez Sánchez , Lucero Valenzuela Carvajal , Luis David Beltrán Ontiveros , Omar Enrique Morales Flores , Ramón Antonio Ruelas Estrada , Airam Acilegna López Mercado ,

Abstract

Background: Kikuchi–Fujimoto disease (KFD) has been reported more frequently in Asian countries. Its clinical course is usually
transient, with spontaneous resolution within 1 to 4 months.
Case Presentation: An 18-year-old male with a history of febrile seizures in childhood presented with 1 month of persistent fever, malaise, rash, and generalized painful lymphadenopathy. On admission, he was tachycardic, febrile, and exhibited significant pancytopenia. Infectious studies were negative, while acute-phase reactants were elevated. Computed tomography imaging revealed systemic lymphadenopathy and hepatosplenomegaly. A lymph node biopsy was performed, demonstrating necrotizing lymphadenitis consistent with KFD. Only after histopathologic confirmation and due to the known association with systemic lupus erythematosus (SLE), immunologic testing was expanded, revealing elevated anti–double-stranded DNA antibodies and positive European Alliance of Associations for Rheumatology/American College of Rheumatology criteria, confirming KFD secondary to lupus. Immunosuppressive therapy was initiated, resulting in clinical and hematologic improvement, and the patient was discharged with follow-up in Rheumatology.
Conclusion: The coexistence of KFD and SLE should be considered in patients presenting with fever, lymphadenopathy, and pancytopenia. Diagnosis relies on histopathologic evaluation to differentiate it from hematologic, infectious, or autoimmune etiologies. Early identification is essential, as KFD is self-limited, whereas SLE requires prompt immunosuppressive therapy.

Keywords: Pancytopenia, lymphadenopathy, systemic lupus erythematosus, Kikuchi–Fujimoto, fever of unknown origin.