What is a notable complication of untreated Mycobacterium leprae infection?

Mycobacterium leprae is the causative agent of leprosy, also known as Hansen's disease. One of the most significant complications associated with untreated leprosy is the development of neuropathy. The bacterium has a predilection for peripheral nerves, leading to nerve damage and subsequent loss of sensation, particularly in the hands and feet. This neuropathy is often characterized by a loss of pain and temperature sensation, which can result in unnoticed injuries or burns, potentially leading to further complications such as secondary infections or disability.

Additionally, the neuropathic changes can cause muscle weakness and atrophy, distorting hand and foot structures and eventually leading to deformities. The clinical presentation of leprosy often includes skin lesions, but these are often secondary to the nerve damage rather than direct complications of the infection itself. Therefore, neuropathy is a hallmark feature of untreated Mycobacterium leprae infection and reflects the importance of timely diagnosis and treatment to prevent irreversible nerve damage and associated complications.