ABSTRACT. Kikuchi's disease (KD), or histiocytic necrotizing lymphadenitis, was initially described in Japan in 1972. In the following years, several series of cases involving patients of different ages, races, and geographic origins were reported, but pediatric reports have been rare.The etiology of KD is unknown, although a viral or autoimmune hypothesis has been suggested. The most frequent clinical manifestation consists of local or generalized adenopathy, although in some cases, it is associated with more general symptoms, multiorganic involvement, and diverse analytic changes (leukopenia, elevated erythrocyte sedimentation rate, and C-reactive protein, as well as an increase of transaminases and serum lactic dehydrogenase).Diagnosis is based on characteristic pathologic findings that permit differentiation of this disease from lymphoma, systemic lupus erythematosus, and infectious lymphadenopathies.We CASE REPORTA 14-year-old white boy was admitted to our hospital after presenting with fever up to 39.8°C for 1 week, malaise, odynophagia, arthralgia, myalgia, abdominal pain, and pruritic skin eruption. Personal and family history was irrelevant. He did not recall any history of exposure to fleas, ticks, cats, or dogs, and there was no indication of animals scratches. On physical examination, several multiple peripheral adenopathies were detected (cervical, axillary, and inguinal), the sizes of which ranged from 0.5 to 2.5 cm in diameter. In general, these nodes were indurated, mobile, and relatively tender. Liver and spleen were palpable 4 cm and 2 cm, respectively, below the costal margin. Erythematous, flat-tipped papules were patent on the face, back, and extremities (Fig 1).Serial blood analyses during the first 2 weeks after admission revealed pancytopenia (2.7 ϫ 10 9 leukocytes/L with normal differential formula and atypical lymphocytes in peripheral blood; 9.3 g/dL hemoglobin; 107 ϫ 10 9 /L platelets). Erythrocyte sedimentation rate was 39 mm per hour, and C-reactive protein was 163 mg/dL. Biochemical analysis, coagulation, hepatic and renal functions, immunoglobulins, and complement count were normal (Tables 1, 2). Rheumatoid factor, antinuclear antibodies, direct Coombs test, and two Mantoux test results proved to be negative. Multiple blood, urine, feces, sputum, and tissue culture results also were negative. Antibody titers against Epstein-Barr, cytomegalovirus, hepatitis, HIV, and Parvovirus B 19 , and serum polymerase chain reaction for herpesvirus type 6 were negative as well, as were results of serologic tests for syphilis, Brucella, toxoplasmosis, Leishmania, Rickettsia, Borrelia, and Bartonella henselae and quintana.Results of chest roentgenography, echocardiography, and bone scan were normal; an abdominal ultrasound examination detected hepatosplenomegaly with uniform density and nephromegaly with increased cortical echogenicity.The patient was treated with ceftriaxone and nonsteroid antiinflammatory drugs during the second week of fever. with apparent lack of remission. Furthermore, the ...