A fatal neonatal case of fungemia due to Exophiala dermatitidis—case report and literature review

BACKGROUND: Systemic infections caused by the black yeast-like fungus Exophiala dermatitidis are rare, but are associated with high mortality especially in immunocompromised patients. We report the first case of E. dermatitidis fungemia in a premature extremely low birth weight (ELBW) neonate who succumbed despite antifungal therapy with liposomal amphotericin (AMB) and fluconazole. A systematic review of all fungemia cases due to E. dermatitidis was also conducted aiming for a better understanding of the risk factors, treatment strategies and outcomes. CASE PRESENTATION: A male, ELBW premature neonate, soon after his birth, developed bradycardia, apnoea and ultimately necrotizing enterocolitis with intestinal perforation requiring surgical intervention. Meanwhile, he had also multiple risk factors for developing bloodstream infection, such as intubation, mechanical ventilation, central venous catheter (CVC), parenteral nutrition, empirical and prolonged antibiotic use. His blood cultures were positive, firstly for Acinetobacter junii and then for Klebsiella pneumoniae together with E. dermatitidis while on fluconazole prophylaxis and antibiotic empiric therapy. Despite the treatment with broad spectrum antibiotics, liposomal AMB and fluconazole, the newborn succumbed. A literature review identified another 12 E. dermatitidis bloodstream infections, mainly in patients with hematologic malignancies and solid organ transplant recipients (61%), with overall mortality 38% despite CVC removal and antifungal therapy. CONCLUSIONS: Due to the rarity of E. dermatitidis infections, little is known about the characteristics of this yeast, the identification methods and the optimal therapy. Identification by common biochemical tests was problematic requiring molecular identification. Resolution of neonatal fungemia is difficult despite proper antifungal therapy especially in cases with multiple and severe risk factors like the present one. Therapeutic intervention may include CVC removal and treatment for at least 3 weeks with an azole (itraconazole or fluconazole after susceptibility testing) or AMB monotherapy but not echinocandins or AMB plus azole combination therapy.