Skin involvement in Kikuchi's disease: an immunocytochemical and immunofluorescence study.

Kikuchi's disease (KD) is a benign self-limiting febrile illness usually affecting young women, which is manifested clinically by fever and cervical lymphadenopathy. Skin involvement in KD is very rare and is evident clinically in the form of skin rashes and nodules. We describe one such case of KD in a 33-year-old Bulgarian woman who presented with cervical and axillary lymphadenopathy and who developed a transient facial rash. Biopsy of axillary lymph nodes showed the characteristic features of KD with infiltration of the lymph node paracortex by apoptotic plasmacytoid monocytes. Biopsies of the facial skin showed two features: (1) dermal infiltration by apoptotic plasmacytoid monocytes; (2) on immunofluorescence studies of frozen sections prepared from involved and uninvolved facial skin, deposition of immunoglobulins and complement at the dermoepidermal junction and in the walls of dermal blood vessels. Such immunofluorescence findings in the skin of patients with KD have never been described. These findings suggest the presence of an autoimmune reaction as a component of KD.