Diagnostic challenges and management of kikuchi-fujimoto disease: a rare case report.

Introduction: Kikuchi-Fujimoto disease, otherwise referred to as histiocytic necrotizing lymphadenitis, is a rare and self-limiting disorder characterized by fever, lymphadenopathy, and upper respiratory symptoms. The main target of the illness is young Asian adults and is more prevalent in females. This disease probably has viral triggering or autoimmune responses, and diagnosis depends on histopathological examination. Case Presentation: We present a case of an 18-month history of recurrent high-grade fever with marked weight loss and an enlarged occipital lymph node in a 42-year-old diabetic male from Karachi, Pakistan. The patient's symptoms did not subside despite being hospitalized several times and receiving multiple courses of antibiotics. Physical examination revealed a firm, non-tender occipital lymph node. Laboratory studies showed mild anemia and leukopenia, raised inflammatory markers, but unremarkable imaging studies and autoimmune tests. An excisional biopsy of the lymph node confirmed KFD with necrotizing lymphadenitis showing characteristic karyorrhectic debris. Discussion: This case epitomizes the diagnostic challenges of KFD, which can mimic a host of conditions like tuberculosis and lymphoma. The recurrent fevers in the presence of significant weight loss and failure to respond to the usual treatments raised suspicion for further detailed investigation. Excisional biopsy established the diagnosis and differentiated it from other conditions. The patient's rapid improvement with corticosteroid therapy aligns with established treatment protocols for KFD, thus proving its efficacy. Conclusion: KFD should be included in the differential diagnosis of fever of unknown origin. Diagnosis and management of KFD can avoid misdiagnosis and hence improve patient outcomes.