Phaeohyphomycoses (brown-black moulds)
Phaeohyphomycosis, a term first introduced by Ajello and colleagues [1], is an encompassing clinical designation for a spectrum of infections caused by darkly pigmented moulds [2, 3]. In its simplest definition, phaeohyphomycosis is an infection caused by fungi that are characterized by a brown-to-black coloration of their vegetative or spore cell walls. Dark pigmentation of the moulds is caused by deposition within the cell wall of dihydroxynaphthalene melanin that is formed through pentaketide metabolism. These moulds collectively are known as dematiaceous fungi. In most cases the brown coloration of the fungus is apparent in host tissue, but at times it is revealed only when the fungus is grown in culture. The term phaeohyphomycosis (phaeo: dusky or brown; hypho: hyphal) is based on characteristics of the fungi as seen in infected tissue and thus includes many genera and species.