Enthesitis-related arthritis in Kikuchi-Fujimoto disease

Histiocytic necrotizing lymphadenitis or Kikuchi-Fujimoto disease (KFD) is a rare, benign and self-limiting disorder that characteristically presents with fever and cervical lymphadenopathy. Articular manifestations in the form of arthralgias are common but frank arthritis is distinctly rare and dactylitis has not been reported yet. Herein, we describe a young boy who presented with arthritis and dactylitis as the initial manifestation of KFD. A 14-year-old boy presented with a two-week history of fever, generalized lymphadenopathy and asymmetric polyarthritis, enthesitis and dactylitis of the toes. Two years earlier he presented with arthritis of the knee and ankle joints, which lasted for 12 months. However, he had been asymptomatic for one year. Investigations revealed anemia, leukopenia and raised acute phase reactants. Work-up for infectious etiology, systemic lupus erythematosus and leukemia and lymphoma was negative. Excision biopsy of the cervical lymph node confirmed KFD. Fever, lymphadenopathy and leukopenia dissipated with nonsteroidal anti inflammatory drug therapy, but the arthritis persisted. A trial of methotrexate led to the resolution of the arthritis.