Mycetoma is a rare chronic granulomatous disease caused by a range of bacteria and fungi. The most common bacteria that cause mycetoma are Actinomyces (the most common cause in India and Africa) and Nocardia (the most common cause in Latin America). Other bacteria that can cause mycetoma include Streptomyces, Pseudonocardia, Amycolatopsis, Veronaea, and Oerskovia.
The exact mechanism of how mycetoma is caused is still unclear, but it is thought to be related to an environmental exposure to the bacteria, either through a wound or insect bite. It is thought that in some cases, the bacteria may be present in the environment and can enter the body through a break in the skin. Once inside the body, the bacteria can multiply and cause an infection that is slow to resolve.
The most common symptoms of mycetoma are a slowly growing lump (granuloma) on the skin, accompanied by swelling, redness, and pain. The granuloma can increase in size over time, and may cause disfigurement and disability. It is possible for the infection to spread to other parts of the body, including the lungs, bones, and joints. Treatment typically involves a combination of antibiotics and surgery to remove the granuloma.