Kikuchi disease was described in 1972 in Japan. It is also known as histiocytic necrotizing lymphadenitis, Kikuchi necrotizing lymphadenitis, phagocytic necrotizing lymphadenitis, subacute necrotizing lymphadenitis, and necrotizing lymphadenitis. Kikuchi disease occurs sporadically in people with no family history of the condition. It was first described by Dr Masahiro Kikuchi (1935–2012) in 1972 and independently by Y. Fujimoto. Signs and symptoms The signs and symptoms of Kikuchi disease are fever, enlargement of the lymph nodes (lymphadenopathy), skin rashes, and headache. In sixty to ninety percent of cases, lymphadenopathy presents in the posterior cervical lymph nodes with diameter enlargement typically being between one to two centimeters, but up to seven centimeters has been reported in literature. Occasionally, the supraclavicular and axillary lymph nodes become swollen as well. Rarely, enlargement of the liver and spleen and nervous system involvement resembling meningitis are seen. Often a bout of extreme fatigue can occur - often taking hold during latter parts of the day and the affected person can be more prone to fatigue from exercise. Pathophysiology Some studies have suggested a genetic predisposition to the proposed autoimmune response. Several infectious candidates have been associated with Kikuchi disease. Many theories exist about the cause of KFD. Microbial/viral or autoimmune causes have been suggested. Mycobacterium szulgai and Yersinia and Toxoplasma species have been implicated. More recently, growing evidence suggests a role for Epstein-Barr virus, as well as other viruses (HHV6, HHV8, parvovirus B19, HIV and HTLV-1) in the pathogenesis of KFD. However, many independent studies have failed to identify the presence of these infectious agents in cases of Kikuchi lymphadenopathy. In addition, serologic tests including antibodies to a host of viruses have consistently proven noncontributory and no viral particles have been identified ultrastructurally. KFD is now proposed to be a nonspecific hyperimmune reaction to a variety of infectious, chemical, physical, and neoplastic agents. Other autoimmune conditions and manifestations such as antiphospholipid syndrome, polymyositis, systemic juvenile idiopathic arthritis, bilateral uveitis, arthritis and cutaneous necrotizing vasculitis have been linked to KFD. KFD may represent an exuberant T-cell-mediated immune response in a genetically susceptible individual to a variety of nonspecific stimuli. Certain Human leukocyte antigen class II genes appear more frequently in patients with Kikuchi disease, suggesting that there may be a genetic predisposition to the proposed autoimmune response. Diagnosis It is diagnosed by lymph node excision biopsy. Kikuchi disease is a self-limiting illness which has symptoms which may overlap