Leprosy, Tuberculoid: A principal or polar form of LEPROSY in which the skin lesions are few and are sharply demarcated. Peripheral nerve involvement is pronounced and may be severe. Unlike lepromatous leprosy (LEPROSY, LEPROMATOUS), the lepromin test is positive. Tuberculoid leprosy is rarely a source of infection to others.Leprosy: A chronic granulomatous infection caused by MYCOBACTERIUM LEPRAE. The granulomatous lesions are manifested in the skin, the mucous membranes, and the peripheral nerves. Two polar or principal types are lepromatous and tuberculoid.Leprosy, Lepromatous: A chronic communicable infection which is a principal or polar form of LEPROSY. This disorder is caused by MYCOBACTERIUM LEPRAE and produces diffuse granulomatous skin lesions in the form of nodules, macules, or papules. The peripheral nerves are involved symmetrically and neural sequelae occur in the advanced stage.Mycobacterium leprae: A species of gram-positive, aerobic bacteria that causes LEPROSY in man. Its organisms are generally arranged in clumps, rounded masses, or in groups of bacilli side by side.Leprosy, Borderline: A form of LEPROSY in which there are clinical manifestations of both principal types (lepromatous and tuberculoid). The disease may shift toward one of these two polar or principal forms.LeprominErythema Nodosum: An erythematous eruption commonly associated with drug reactions or infection and characterized by inflammatory nodules that are usually tender, multiple, and bilateral. These nodules are located predominantly on the shins with less common occurrence on the thighs and forearms. They undergo characteristic color changes ending in temporary bruise-like areas. This condition usually subsides in 3-6 weeks without scarring or atrophy.Leprostatic Agents: Substances that suppress Mycobacterium leprae, ameliorate the clinical manifestations of leprosy, and/or reduce the incidence and severity of leprous reactions.Leprosy, Multibacillary: A form of LEPROSY classified by the World Health Organization for the purpose of treatment, based on clinical manifestations and skin smear results. Patients with multibacillary leprosy have six or more lesions with or without positive skin smear results for the causative agent MYCOBACTERIUM LEPRAE. Multibacillary leprosy encompasses borderline lepromatous, midborderline, and lepromatous leprosy.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Tuberculoma: A tumor-like mass resulting from the enlargement of a tuberculous lesion.Armadillos: Burrowing, chiefly nocturnal mammals of the family Dasypodidae having bodies and heads encased in small bony plates. They are widely distributed in the warmer parts of the Americas.Leprosy, Paucibacillary: A form of LEPROSY classified by the World Health Organization for the purpose of treatment, based on clinical manifestations and skin smear results. Patients with paucibacillary leprosy have fewer than six skin lesions with no causative agent MYCOBACTERIUM LEPRAE on any slit-skin smear testing. Paucibacillary leprosy encompasses indeterminate, borderline tuberculoid, and tuberculoid leprosy.Dapsone: A sulfone active against a wide range of bacteria but mainly employed for its actions against MYCOBACTERIUM LEPRAE. Its mechanism of action is probably similar to that of the SULFONAMIDES which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with PYRIMETHAMINE in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Tuberculosis, Cutaneous: Tuberculosis of the skin. It includes scrofuloderma and tuberculid, but not LUPUS VULGARIS.Granuloma: A relatively small nodular inflammatory lesion containing grouped mononuclear phagocytes, caused by infectious and noninfectious agents.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Glycolipids: Any compound containing one or more monosaccharide residues bound by a glycosidic linkage to a hydrophobic moiety such as an acylglycerol (see GLYCERIDES), a sphingoid, a ceramide (CERAMIDES) (N-acylsphingoid) or a prenyl phosphate. (From IUPAC's webpage)BCG Vaccine: An active immunizing agent and a viable avirulent attenuated strain of Mycobacterium tuberculosis, var. bovis, which confers immunity to mycobacterial infections. It is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Mycobacterium bovis: The bovine variety of the tubercle bacillus. It is called also Mycobacterium tuberculosis var. bovis.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Mycobacterium: A genus of gram-positive, aerobic bacteria. Most species are free-living in soil and water, but the major habitat for some is the diseased tissue of warm-blooded hosts.Clofazimine: A fat-soluble riminophenazine dye used for the treatment of leprosy. It has been used investigationally in combination with other antimycobacterial drugs to treat Mycobacterium avium infections in AIDS patients. Clofazimine also has a marked anti-inflammatory effect and is given to control the leprosy reaction, erythema nodosum leprosum. (From AMA Drug Evaluations Annual, 1993, p1619)Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.HLA-DR Antigens: A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Mycobacterium tuberculosis: A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Monocytes: Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.