Case Presentation: A 28 year old Nepali female presented with convulsive activity and one week of progressive changes in behavior and mental acuity. She had polyarthralgia, painful cervical lymph nodes, malar rash, subjective fever, headaches, and fatigue for 2 months. Previous workup revealed positive antinuclear antibody (ANA), anti-ribonuclearprotein (RNP), and anti-Ro antibodies with no formal diagnosis. On presentation, she appeared lethargic with a malar rash, tender lymphadenopathy in the cervical and axillary areas, and altered mental status. Throughout her hospital stay, she began having high fevers and was leukopenic. Further laboratory studies demonstrated positive anti-double stranded DNA (anti ds-DNA) and anti-smith antibodies. A diagnosis of systemic lupus erythematosus (SLE) was made and her neurological manifestation was thought to be lupus cerebritis. A lymph node biopsy of the right axilla revealed necrotizing lymphadenitis without presence of granulocytic infiltration. Small lymphocytes were present in the background intermixed with scattered plasma cells as well as focal foamy cell infiltrates. Based on the histologic features, Kikuchi-Fujimoto disease (KFD) was part of the differential diagnosis. The patient’s condition continued to worsen, and she was started on pulse dose methylprednisolone and intravenous (IV) cyclophosphamide. Just two days after initiation of medication, she had drastic improvement. Methylprednisolone was transitioned to prednisone with continuation of monthly infusion of cyclophosphamide.
Discussion: KFD, a benign form of histiocytic necrotizing lymphadenitis, is characterized by fever and cervical lymphadenopathy more frequently diagnosed in young female Asians. Systemic symptoms can include weight loss, arthralgias, night sweats, rash, fatigue, and hepatosplenomegaly. Although the etiology of KFD is still uncertain, the two most accepted hypotheses are infectious and autoimmune. SLE is the most common autoimmune condition associated with KFD. As KFD can imitate various diseases, the most reliable way to make the diagnosis is through a lymph node biopsy. Histologically, KFD is characterized by geographic necrosis of lymph node with foci of abundant karyorrhectic fragments and apoptotic cells surrounded by histiocytes. Additional features include absence of neutrophils and eosinophils. The clinical course of KFD is benign in majority of patients, often resolving within 6 months. However, if KFD occurs simultaneously with SLE, the course can be more aggressive and treatment with short pulses of corticosteroids should be initiated. For those with symptoms involving extranodal tissues, treatment with additional immunosuppressive drugs such as cyclophosphamide or hydroxychloroquine may also be beneficial.
Conclusions: It is important to recognize the association of KFD with other autoimmune disease. Long-term prognosis is favorable for most patients with KFD, but follow-up is still necessary to monitor for recurrence or development of autoimmune disease.