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Tuberculoid leprosy is a chronic bacterial infection that occurs throughout the world. This infectious disease is caused by the Mycobacterium leprae bacteria. The bacteria cause lesions to appear on the skin, mucous membranes, or testes. The eyes may also be affected as well as peripheral nerves, such as the hands and feet. Antibiotics are effective against the causative bacteria, and this type of leprosy can be cured with the appropriate treatment.
There are two types of leprosy — tuberculoid and lepromatous. Tuberculoid leprosy is characterized by the occurrence of very few lesions and minimal bacteria. Lepromatous leprosy can be a widespread infection involving many lesions containing large amounts of bacteria. Borderline leprosy is not a type of leprosy but is a class between the two leprosy types. Patients with borderline leprosy have more lesions than what is classified as tuberculoid but fewer than the more serious lepromatous leprosy.
The most distinctive symptom of leprosy are the hairless skin lesions that are usually numb to the touch. They may be flat or slightly raised, and they are usually a darker color than the surrounding skin. To be classified as tuberculoid leprosy, there must be fewer than five lesions present. If there are five or more lesions, the leprosy is classified as borderline or lepromatous. A secondary symptom, peripheral nerve involvement, causes a progressive numbness of the hands, feet, and sometimes, the face.
Clinical presentation is the main diagnostic criteria in determining tuberculoid leprosy. The physician examines the patient for lesions, noting the size, color, and number of lesions present. Peripheral nerve areas are checked for weakness or numbness. A definitive diagnosis is then made by lancing the lesion and obtaining fluid for a smear. The fluid from tuberculoid lesions, as opposed to lepromatous lesions, does not contain Mycobacterium leprae bacteria.
Left untreated, tuberculoid leprosy may resolve on its own or progress to a more serious form. A long-term infection can cause permanent damage and disfigurement. The standard treatment is a six-month course of rifampin and dapsone. If only a single lesion is present, the patient is treated with a single combined dose of rifampin, ofloxacin, and minocycline. Patients are considered noninfectious shortly after antibiotic treatment has begun.
Leprosy is contracted through exposure to nasal secretions from infected persons. Before the discovery of antibiotics, infected people were often kept isolated in leper colonies. Some leper colonies still exist, particularly in areas where treatment is not readily available, but most leprosy patients can live normal lives after being treated with antibiotics.