Invasive fusariosis is a severe infection in patients with profound neutropenia, particularly in the setting of acute myeloid leukemia (AML). Diagnosis is often delayed, and cutaneous manifestations may be the first and most accessible sign of hematogenous dissemination. This is a case report of a 66-year-old male patient diagnosed with AML in February 2025, hospitalized for induction chemotherapy. On February 25, he developed febrile neutropenia and was started on cefepime, later showing a blood culture positive for multisusceptible Klebsiella pneumoniae. On March 1, a painful lesion was noted on the fourth toe of the right foot, compatible with intertrigo. On March 6, a skin biopsy was performed and, on the same day, multiple papular, umbilicated, and necrotic skin lesions appeared over the back, abdomen, and lower limbs, with worsening of the foot lesion, showing erythema and local necrosis. Nasal mucosa was evaluated by otorhinolaryngology without abnormalities. He had been on fluconazole prophylaxis since the beginning of treatment, and serial galactomannan tests were negative. On March 7, due to clinical worsening, amphotericin deoxycholate was initiated under the hypothesis of invasive fungal disease. Chest CT showed bilateral centrilobular micronodules up to 3 mm, and paranasal sinuses were unremarkable. Blood culture from March 6 confirmed growth of Fusarium sp. after a few hours of incubation. The patient progressed to hemodynamic instability and was transferred to intensive care, precluding surgical debridement. Treatment was switched to liposomal amphotericin B (5 mg/kg/day). Despite interventions, the patient died on March 25, 2025. In immunosuppressed patients, fusariosis manifests with refractory fever, characteristic skin lesions, and a high rate of positive blood cultures due to in vivo sporulation. Cutaneous lesions, often painful with central necrosis, may mimic ecthyma gangrenosum and occur at multiple stages of evolution (papules, nodules, ulcerations). Preexisting intertrigo or onychomycosis may serve as a portal of entry. Radiologically, centrilobular micronodules on chest imaging suggest pulmonary involvement. Prognosis remains poor, with mortality of 70–80% in prolonged neutropenia, even with aggressive antifungal therapy.
Castro et al. (Sun,) studied this question.