Isavuconazole Breakthrough Disseminated *Fusarium fujikuroi* Infection in a Patient with Allogeneic Hematopoietic Stem Cell Transplant: Diagnostic and Therapeutic Challenges – A Case Report

# Introduction This case report illustrates the diagnostic challenges and complexities in treatment of disseminated fusariosis. Case An 18-year-old patient received a second allogeneic hematopoietic stem cell transplant (HSCT) 5 months after first HSCT. Two days post-transplant, presented neutropenic fever with diffuse multiple cutaneous papular lesions under isavuconazole prophylaxis. A diagnosis fusariosis due to *Fusarium fujikoroi* was established. Antifungal therapy had be adapted times for efficacy safety issues. Long-term combination posaconazole terbinafine efficiently controlled infection well tolerated. Discussion three major teaching points: (i) high clinical suspicion based on typical microbiologic findings is key factor fusariosis; (ii) challenging variable antifungal agent minimal inhibitory concentrations (MICs); (iii) long-term administration voriconazole can associated multiple, less frequently seen adverse events. Conclusion Typical skin positive blood cultures molds should promptly rise Amphotericin-B are first-line agents Second-line such as used.