Kikuchi-Fujimoto Disease: A Case of Lymphadenitis Following COVID-19 Infection

Introduction: Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare disease of uncertain origin proposed to be secondary to viral or autoimmune causes. It presents as unilateral cervical lymphadenopathy and fever, typically resolving within a few months, however, it mimics malignant lymphoma, leading to extensive work-up fearing malignancy. Case History: A 33-year-old female with a history of Sj？gren’s syndrome, rheumatoid arthritis (not on immunosuppressive therapy) and recent COVID-19 infection two months ago presented with episodes of flu-like symptoms; fever (101？F), chills, and myalgias for two months. Upon evaluation, she had leukopenia (WBC 1.8 k/uL), neutropenia (1.0 k/uL), elevated CRP (134 mg/L), and CT neck demonstrated multiple enlarged cervical lymph nodes with necrosis. The patient was started on Cefdinir and doxycycline for a possible atypical infection given neutropenic fevers and the patient continued to have fevers. A biopsy showed focal necrosis with no evidence of malignancy, suggesting KFD that was likely triggered by a recent COVID infection. She was treated with Prednisone and naproxen, which led to an improvement in symptoms and recovery of her pancytopenia. Discussion: This case is unique since the patient’s recent infection with COVID-19 may have triggered the clinical manifestations of KFD. There have been a few case reports of children who were diagnosed with KFD after a COVID-19 infection and adults diagnosed with KFD following COVID vaccinations; however, this is the first case report involving a young adult in her thirties who was diagnosed with KFD two months after COVID-19.