To the Editors: Candida krusei is an emerging nonalbicans Candida species recognized as a potentially multidrug resistant fungal pathogen.1 The incidence of C. krusei fungemia is highest in leukemic patients and less frequent in neonates.2 We report the first case of refractory candidemia by C. krusei successfully treated with caspofungin in a premature infant. CASE REPORT A 1160 g male infant was delivered vaginally at 26 weeks of gestational age. His mother had been admitted 5 days earlier to our institution for preterm premature rupture of membrane and had received steroids and antibiotic therapy. The infant did not need respiratory support or supplemental oxygen after delivery. An umbilical venous catheter was placed and empiric ampicillin plus gentamicin therapy instituted. On day 4, fluconazole prophylaxis (3 mg/kg twice a week) was begun. On day 5, a percutaneous inserted central catheter (PICC) was placed, and the umbilical catheter was removed. On day 17, a peripheral blood culture was performed because of the appearance of thrombocytopenia, apnea, hyporeactivity, and fever; the infant required intubation and mechanical ventilation. The PICC was removed and replaced with a new one at another site. Two days later, C. krusei colonies grew from the day 17 blood culture. Based on antifungal susceptibility testing, liposomal amphotericin-B (LAmB, 3 mg/kg/d), already started on day 17, was continued and fluconazole was discontinued. One week later, LAmB was increased to 5 mg/kg/d after a second blood culture was positive for C. krusei. Renal and cerebral ultrasound, echocardiogram, and eye examinations were repeatedly normal. Chest radiograph and liver ultrasound were suggestive of Candida end-organ dissemination. On day 41, after 22 days of LAmB treatment and with a third positive blood culture, caspofungin was added in a dosage of 50 mg/m2/d (7 mg/d), without a loading dose. The infant had a prompt improvement; thrombocytopenia (previously requiring 11 platelet transfusions) resolved, and 5 days later the infant was extubated and resumed enteral nutrition. The PICC was removed. LAmB was discontinued after 5 days of combined therapy. Blood cultures performed on the 6th and 11th days of caspofungin treatment were negative. The infant, already suffering cholestasis [total bilirubin, 4.7 mg/dL, direct bilirubin, 2.5 mg/dL, alanine aminotransferase (ALT), 54 U/L, aspartate aminotransferase (AST), 140 U/L], showed acute liver failure since the 3rd day of caspofungin therapy. The dosage of caspofungin was reduced to 5 mg/d and 3.5 mg/d on 4th and on 11th day of therapy, respectively. Treatment lasted 12 days. Liver enzymes peaked at 346 (ALT) and 744 (AST) 3 days after caspofungin withdrawal to normalize thereafter in 2 months. Elevation of liver enzymes and direct bilirubin values during caspofungin therapy has been previously reported in neonates.3 The infant is now 6 months old, is thriving well and shows normal neurologic development at the ongoing follow-up. Fabio Natale, MD Antonella Castronovo, MD Daniela Regoli, MD Mario De Curtis, MD Department of Pediatrics “La Sapienza” University of Rome Rome, Italy Paolo Manzoni, MD Division of Neonatology and NICU S. Anna Hospital Turin, Italy