Kikuchi-Fujimoto disease initially presenting with severe digestive symptoms and progressing to systemic lupus erythematosus: a case report and literature review.

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare idiopathic inflammatory disorder characterized by low incidence and a propensity for misdiagnosis. Although its etiology remains elusive, KFD is often linked to underlying autoimmune conditions. Definitive diagnosis requires lymph node biopsy. Classically, patients present with cervical lymphadenopathy and fever; however, this report describes an atypical, severe manifestation in a patient whose initial symptoms were dominated by prominent gastrointestinal involvement, including abdominal pain and vomiting. Histopathological evaluation of an excised lymph node confirmed the diagnosis. While corticosteroid therapy led to resolution of KFD symptoms, the patient's course was further complicated by the subsequent onset of systemic lupus erythematosus (SLE). Targeted immunosuppressive therapy for SLE ultimately achieved sustained remission. This case underscores the diagnostic pitfalls of KFD with an atypical gastrointestinal prodrome, reaffirms its established yet pivotal association with SLE, and advocates for vigilant long-term surveillance in affected individuals.