Subcutaneous Mycoses

Fungi that cause classic subcutaneous mycoses grow in the soil and on dying plants. They penetrate through skin injuries into the subcutaneous connec­tive tissue, where they cause local, chronic, granulomatous infections. These infections are seen mainly in the tropics and subtropics.

Sporotrichosis is caused by Sporothrix schenckii, a dimorphic fungus that grows as yeast cells in host tissues. Sporotrichosis is characterized by an ulcerous primary lesion, usually on an extremity, and multiple nodules and abscesses along the lymphatic vessels.

Chromomycosis (also chromoblastomycosis) can be caused by a number of species of black molds. The nomenclature of these pathogens is not firmly established. Weeks or months after the spores penetrate into a host, wartlike, ulcerating, granulomatous lesions develop, usually on the lower extremities.

Madura foot or mycetoma can be caused by a wide variety of fungi as well as by filamentous bacteria (Nocardia sp., Actinomadura madurae, Streptomyces somaliensis). Potential fungal contributors include Madurella sp., Pseudoal- lescheria boydii, and Aspergillus sp. The clinical picture is characterized by subcutaneous abscesses, usually on the feet or hands. The abscesses can spread into the musculature and even into the bones. Fistulae are often formed.

References

Kayser, F. H. (2005). Medical Microbiology. Thieme Stuttgart. New York.