Kikuchi-Fujimoto disease associated with systemic lupus erythematosus in an adolescent patient: case report and diagnostic challenges.

BACKGROUND

Kikuchi-Fujimoto disease is a disorder that can mimic lymphoma and present with clinical and histopathological overlap with systemic lupus erythematosus in adolescent patients.

CASE REPORT: A 15-year-old female patient presented with recurrent upper respiratory tract infections. Concomitantly, she developed morning arthralgia in the bilateral metacarpophalangeal joints and a photosensitive malar rash. Subsequently, she developed persistent intermittent fever, anorexia, joint limitation, and cervical and inguinal lymphadenopathy, associated with normocytic normochromic anemia. Complete blood count revealed leukopenia and progressive anemia. Bone marrow biopsy showed increased cellularity with erythroid hypoplasia and reactive megaloblastic changes. Immunohistochemical staining revealed reactive polyclonal lymphoid hyperplasia. During her hospitalization, oral ulcers, jaundice, a skin rash, and elevated transaminases and direct bilirubin were detected. She developed bilateral pleural effusion, acute respiratory failure, and required mechanical ventilation. Positive antinuclear antibodies were documented: 1:640 (AC-20 pattern), leading to a diagnosis of systemic lupus erythematosus. Treatment was initiated with high-dose corticosteroids, intravenous immunoglobulin, and cyclophosphamide for refractory lupus pneumonitis, with initial clinical improvement. She was transferred to a tertiary care hospital; however, she experienced progressive multisystem deterioration and died despite the treatment.

CONCLUSIONS

Early recognition of the overlap between Kikuchi-Fujimoto disease and systemic lupus erythematosus is essential to avoid treatment delays and guide the timely prescription of immunosuppression in severe cases. Prolonged clinical surveillance and close follow-up are crucial for the timely detection of complications and to optimize patient prognosis.