infectious diseases
Mycetoma
Introduction
Mycetoma is a chronic, progressive, local infection caused by fungi or bacteria and involving the feet, upper extremities, or back. Symptoms include tumefaction and formation of sinus tracts. Diagnosis is clinical, confirmed by microscopic examination of exudates and culture. Treatment includes antimicrobials, surgical debridement, and sometimes amputation. (See also Overview of Fungal Infections .) Bacteria, primarily Nocardiosis species and other actinomycetes, cause more than half the cases. The remainder are caused by about 20 different fungal species. When caused by fungi, the lesions are sometimes called eumycetoma. Mycetoma occurs mainly in tropical or subtropical areas, including the southern United States. Mycetoma occurs in equatorial regions of Africa, Latin America, and Asia known as the “mycetoma belt.” Fungal mycetoma (also known as eumycetoma) is the most common type in Africa. Bacterial mycetoma (sometimes referred to as actinomycetoma) causes most cases in South and Central America and in some Asian countries. Mycetoma is acquired when organisms enter through sites of penetrating local trauma on bare skin of the feet or on the extremities or backs of workers carrying contaminated vegetation or other objects. Men aged 20 to 40 are most often affected, presumably because of trauma incurred while working outdoors. Infections spread through contiguous subcutaneous areas, resulting in tumefaction and formation of multiple draining sinuses that exude characteristic grains of clumped organisms. Microscopic tissue reactions may be primarily suppurative or granulomatous depending on the specific causative agent. As the infection progresses, bacterial superinfections can develop. 