Phellinus species: An emerging cause of refractory fungal infections in patients with X‐linked chronic granulomatous disease

Summary Aspergillus spp. are a leading cause of mortality in chronic granulomatous disease ( CGD ), but other fungi have emerged in the era of mould prophylaxis. Of these, Phellinus spp. are an under‐recognised cause of invasive fungal infections ( IFI s) in CGD , and data on their presentation and management are scarce. We present a patient with CGD who developed disseminated IFI involving the lungs and brain. Surgical specimens grew a basidiomycete which was disregarded as a contaminant. After three months of progressive disease despite antifungals, he was diagnosed with Phellinus tropicalis by internal transcribed spacer ( ITS ) sequencing. He improved with amphotericin B and isavuconazole but required haematopoietic stem cell transplantation ( HSCT ). We review the literature on Phellinus infections in CGD and conclude that: (i) these infections emerge on mould‐active prophylaxis and are indolent; (ii) they typically cause locally destructive disease but can disseminate; (iii) diagnosis is delayed and requires molecular methods; (iv) amphotericin B is most active in vitro; and (v) treatment is protracted and requires surgery and possibly HSCT . In conclusion, Phellinus spp. are emerging pathogens in CGD . Every effort should be made to establish the diagnosis of non‐ Aspergillus IFI s in patients with CGD by sending tissue specimens for molecular diagnostics.