Kikuchi's disease: an uncommon cause of fever of unknown origin.

Kikuchi's disease or histiocytic necrotizing lymphadenitis is an uncommon clinical condition that causes diagnostic difficulties because of its lack of specific signs, symptoms and serological markers. Diagnosis is based on histopathological findings, but overlapping of the histological features requires a differential diagnosis among histiocytic necrotizing lymphadenitis and a number of infectious, autoimmune and lymphoproliferative lymphadenopathies. We report a case of Kikuchi's disease in a 19-year-old woman presenting with generalized lymphadenopathy and persistent fever.