Kikuchi’s Disease Masquerading as Prolonged Fever

Abstract

Sir, Kikuchi-Fujimoto Disease (KFD) or histiocytic necrotizing lymphadenitis is a self-limiting disorder of unknown origin, characterized by painful cervical lymphadenopathy with prolonged fever. Being self-limiting in nature, it needs differentiationfromother causesofcervicallymphadenopathy and fever to avoid unnecessary investigations. A 12 y-old boy presented with history of high grade fever for 3 wk. Systemic examination was non-contributory. At admission, investigations revealed hemoglobin 126 g/L, total leucocyte count 4000/uL (neutrophils 50 %, lymphocytes 44 %, monocytes 4 %, eosinophils 2 %), platelets 3.5×10 9 /uL; ESR 40 mm/h; CRP 14 mg/L. Liver and renal functions were normal. Blood cultures were sterile; Mantoux test nonreactive; Widal test and malarial smears negative. Anti-nuclear antibody (ANA) was positive (2+ speckled pattern), however antidsDNA antibody titres were normal. He received empiric antimicrobials and antipyretics. On day 4 of hospitalization, total leucocyte count dropped to 2300/uL (neutrophils 60 %, lymphocytes 36 %, monocytes 2 %, eosinophils 2 %). Bone marrow aspiration was done but was normal. On day 6, he developed right posterior cervical lymphadenopathy which were tender, maximum size being 5×5 cm. No other lymph nodes were affected. Fine needle aspiration cytology (FNAC) from the affected lymph nodes revealed reactive population of lymphoidcells comprisingof lymphocytes, macrophages,and immunoblasts along with patchy necrosis (Fig. 1). Nuclear debris (karyorrhexis) and foamy macrophages showing focal lymphophagocytosis were also seen. No eosinophils or granulomas were found and stain for acid fast bacilli were negative. The findings were consistent with KFD. Resolution of fever, lymphadenopathy and leucopenia occurred after 10 d of supportive care in the hospital. KFD is a rare, self-limiting condition with unknown etiology. Lymphadenopathy and fever are the commonest presenting manifestations. The unique feature seen in our patient was prolonged fever of 4 wk duration and appearance of lymphadenopathy on day 28 of fever due to which investigations for prolonged pyrexia were sought. Such a presentation has been rarely reported before; lymphadenopathy occurring on day 30