Kikuchi-Fujimoto Disease: Report of a Case with Progression to Lupus Nephritis.

BACKGROUND Kikuchi-Fujimoto disease (KFD) is an enigmatic disease, with a distinctive histopathology and a benign and self-limited course. It is more frequent in young Asian women. Autoimmune diseases are identified as one of its triggers; primarily SLE, which may precede, be concomitant with, or develop after the diagnosis of KFD. Patients with KFD should receive periodic follow-up for several years to detect possible evolution of SLE. The main feature of KFD is lymphadenopathy, and cervical lymph nodes are involved in 50% to 98% of cases. Other symptoms such as fever, fatigue, weight loss, and arthralgias are also reported. Differential diagnosis between KFD and SLE is a challenge. When KFD and SLE coexist, a lymph node biopsy may be diagnostic. Treatment should be symptomatic with analgesics and anti-inflammatories, with complete resolution in 3 to 4 months. Corticosteroids and immunosuppressive therapy are justified only in cases concomitant with SLE. CASE REPORT We report a case of KFD in a 28-year-old woman who was initially negative for anti-nuclear antibodies (ANA) and anti-double-stranded deoxyribonucleic acid antibodies (anti-dsDNA), but who became antibody-positive and presented with lupus nephritis 2 months later. CONCLUSIONS We present a case of a patient with KFD who developed SLE 2 months later; highlighting the importance of recognizing its association and its possible progression to monitor for future development of SLE and provide timely treatment to avoid complications. We also compared the clinical, laboratory, and histological similarities between the 2 entities.