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. : 324  It can be associated 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. Clinical signs of phaeohyphomycosis
Wildlife
Phaeohyphomycosis is found throughout the animal kingdom. From molluscs to humans, different strains of this fungus affect animals differently, based on how severely the fungus has infected the animal. The clinical signs depend on the species of animal that is infected as well as the strain of fungus it is infected with. This disease is usually found more often in stressed animals after removal from their habitat. Invertebrates
Invertebrates, such as crabs and mollusks, show a variety of clinical signs. Crabs had increasingly weak motor control, especially in legs and claws, and were lethargic. They had poor balance and tetany, or muscle spasms, in the claws.
While death is rare among MAC patients, it can occasionally metastasize to local lymph nodes. The 10 year overall survival rate is 86.4%, however this is exceedingly close to many 10 year survival rates of populations without MACs present. Causes
Little is known about the causes of MACs, although some evidence has shown that ultraviolet light, radiation, and genes may be causation factors. A genetic role might also be plausible, according to some studies. In several cases, patients developed a MAC after immunosuppression. Treatment
Due to the invasive nature of MACs, most cases are treated with wide local excision in order to decrease the rate of reoccurrence. Increasingly however, Mohs micrographic surgery is being employed as it allows more specific margins to be removed, along with decreasing the size of postoperative scars and disfigurement. In rare cases, tumors can be deemed inoperable due to their size and location under vital structures of the face. Chemotherapy and radiation treatment have been used when metastasis has occurred or when an excision cannot be performed, but results have been inconclusive about their effectiveness. In some cases, radiation therapy has been shown to increase tumor size. While in other cases, it implies that it will decrease the success of the tumor regrowing. Long term follow-up is necessary, as some cases of local recurrence have been documented 30 years after the original diagnosis. See also
Syringofibroadenoma
Skin lesion
List of cutaneous conditions


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