Mycetoma is a term for a subcutaneous infection caused by either by bacterial (actinomycetes, most important representative being Nocardia sp.) or fungal (eumycetoma) pathogens. The condition is chronic and may be severely debilitating, with main clinical features being development of painless communicating nodules on distal lower extremities.
Mycetoma is most frequently encountered among males between 20-50 years living in countries along the equator. The prevalence is mostly seen in Mexico, Venezuela, Somalia, Senegal, Yemen, Sudan, and India. Inoculation of the organism after trauma is the predominant mode of infection, which is perhaps one of the reasons why the condition is more common among barefoot-walking populations   . Peasants and agriculture workers are at a particular risk for acquiring mycetoma, making occupational factors important in the pathogenesis . A painless, firm mass containing numerous communicating nodules and abscesses is the typical lesion of mycetoma   . The feet are affected in the majority of cases, while hands and the trunk are other potential sites . Nodular communication through the development of fistulas results in the release of a syrup-like purulent or seropurulent discharge that contains grains formed by the causative agent . In some patients, a prolonged infection can lead to dissemination of pathogens into the skeletal system and the systemic circulation, causing bacteremia or even life-threatening sepsis . The clinical course of mycetoma (also know as Madura's foot, named after the Indian endemic region of Madura) is rapid and amputation may be frequently indicated due to the extreme disfiguring of the distal extremities by nodular breakdown .
A properly obtained patient history containing information about the course of symptoms and occupancy may reveal the possible mode of infection and consequently, the underlying pathogen. Moreover, communicating nodular lesions and syrup-like exudate can be observed during a physical examination, which could be sufficient to make a presumptive diagnosis. In fact, the color of grains can indicate the cause of mycetoma in active phases of the disease - white, yellow or red grains are suggestive of bacterial etiology, while fungal grains are usually black or pale  . To confirm mycetoma, however, several diagnostic procedures should be used :