Phaeohyphomycosis

Phaeohyphomycosis
SpecialtyInfectious diseases
Symptoms
CausesBreathing in or entry via a cut in the skin of dark filamentous fungi
Diagnostic methodHistology, culture, PCR
Differential diagnosisAspergillosis, chromoblastomycosis, cryptococcosis, mycetoma
TreatmentSurgical debridement/drainage, antifungals
MedicationItraconazole, amphotericin B
FrequencyRare

Phaeohyphomycosis is a diverse group of fungal infections, caused by dematiaceous fungi whose morphologic characteristics in tissue include hyphae, yeast-like cells, or a combination of these. It can be associated with an array of melanistic filamentous fungi including Alternaria species, Exophiala jeanselmei, and Rhinocladiella mackenziei.

The term "phaeohyphomycosis" was introduced to determine infections caused by dematiaceous (pigmented) filamentous fungi which contain melanin in their cell walls. Phaeohyphomycosis is an uncommon infection, but the number of cases reported has been increasing in recent years. Fungal melanin is thought to be a virulence factor. The outcome of antifungal treatment is poor, and mortality is almost 80%. Phaeohyphomycosis has been attributed to more than 100 species and 60 genera of fungi over the past several decades. The pathogens are considered opportunistic. Almost all cases of widely disseminated infection have occurred in immunosuppressed people.