[Clinical investigation of nine pediatric Japanese spotted fever cases]

To clarify the clinical manifestations of pediatric Japanese spotted fever (JSF), which remain unclear, we retrospectively reviewed the records of 9 consecutive hospitalized children 5 boys and 4 girls aged 0-15 years (median: 2.3) whose diagnosis was patients with JSF who were serologically confirmed from April 2008 to October 2009. We initially studied the polymerase chain reaction (PCR) assay validity for specific Rickettsia japonica DNA in the blood. We also studied febrile duration, the history of contact with tick-infested areas, body temperature, eschars at tick bite sites, skin rash, treatment drugs, and laboratory data. Five of the 9 (56%) had positive PCR tests. Prehospitalization febrile duration was 1-5 days. Five had had contact with tick-infested areas and 4 had not despite living near such areas. Body temperature was 40 degrees C in 7. Only 4 had eschars at bite sites. Characteristic spotted palmar and/or plantar erythema seen in 8 was useful in diagnosis. Laboratory studies showed typical hyponatremia of < 135mEq/L in 6 JSF was diagnosed easily at hospitalization in 7. Diagnosis in a 2-month-old infant proved difficults, however, worsening the child's condition and causing hepatosplenomegaly, thrombocytopenia, anemia, and hyperferritinema. The infant was treated with high-dose gamma-globulin and azithromycin (AZM) followed by minocycline (MINO). Another case was difficult to diagnose due to clinical manifestations consistent with Kawasaki disease. The child was treated with high-dose gamma-globulin and AZM. Three of the 9 were treated with MINO alone and 4 with combined MINO and new quinolones. Fever was resolved within 2 days of treatment in all cases. Our findings show that children with high fever and spotted palmar and/or plantar erythema should be treated immediately for JSF in prevalent areas, even in the absence of eschars.