![]() It has been suggested that the term “dematiaceous” is not appropriate given its etymologic derivation from the Greek “deme,” meaning bundle, though it has become fairly entrenched in medical mycological literature and will likely persist in nomenclature ( 574). “Phaeo” comes from the Greek meaning “dark” and has been commonly used, particularly when describing infections due to these fungi as “phaeohyphomycosis,” i.e., infection caused by dark-walled fungi, as suggested by Ajello et al. “Phaeoid,” “phaeo-sporotrichose,” and “dematiaceous” have also been mentioned in the literature ( 574). As Sporothrix schenckii was one of the earliest melanized fungi described, “sporotrichoid” was often used to describe similar fungi, though currently it has been replaced by other, more useful terms. The terms used to describe these fungi have evolved over the past several decades. This review will focus on fungi that are considered to be melanized as a primary feature, particularly with regard to their phenotypic appearance (macroscopic and microscopic morphologies) and appearance in tissue (histology). ![]() In recent years its pathogenic role in fungi has become well described ( 123, 292, 375, 460, 546). Its functions are varied but are based on the unique molecular characteristics of its structure, which make it an extremely stable molecule, resistant to a variety of destructive physicochemical processes ( 83, 109, 324). Melanin is a ubiquitous compound found in many microbes and animals. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Therapy varies depending upon the clinical syndrome. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Melanin is a likely virulence factor for these fungi. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. ![]() The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Summary: Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes. ![]()
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