Lupus Meets Kikuchi: A Diagnostic Dilemma Unfolding with Respiratory Failure - A Case Report

Kikuchi-Fujimoto disease (KFD) is a rare, self-limiting lymphadenitis of unclear etiology that can mimic systemic lupus erythematosus (SLE) both clinically and histopathologically. When SLE and KFD co-exist, diagnostic clarity becomes challenging, especially in the setting of acute respiratory failure—a manifestation more typical of SLE than KFD. An 18 years old female presented with complaints of fever since one month and she was apparently asymptomatic until one month after which she had developed fever with high grade associated chills, intermittent fever, She had characteristic rashes over bilateral arms was present. Laboratory workup was notable for HPE(Histopathological Examination) reports shows Suggestive of Lupus Lymphadenitis, sectional lymph node showed with focal areas of Necrosis, Karyo-orrhectoc debris, leuko-cytoclastic vasculitis and fibrinoid necrosis in the sub-cortical region. During the hospital stay patient had desaturated and respiratory examination showed Bilateral infiltration coarse crepitation was present. And the chest x-ray showed bilateral lung shadows.This case underscores the diagnostic challenge in distinguishing KFD from SLE, particularly when both diseases may co-exist. Timely recognition and treatment of lupus pneumonitis are critical to patient outcomes. The overlap between Kikuchi-Fujimoto disease and systemic lupus erythematosus presents a diagnostic dilemma, particularly when severe manifestations such as respiratory failure occur. A high index of suspicion and multidisciplinary collaboration are essential to guide diagnosis and management.