What is leprosy?
Leprosy is a disease mainly caused by the bacteria Mycobacterium leprae, which causes damage to the skin and the peripheral nervous system. The disease develops slowly (from six months to 40 years) and results in skin lesions and deformities, most often affecting the cooler places on the body (for example, eyes, nose, earlobes, hands, feet, and testicles). The skin lesions and deformities can be very disfiguring and are the reason that historically people considered infected individuals outcasts in many cultures. Although human-to-human transmission is the primary source of infection, three other species can carry and (rarely) transfer M. leprae to humans: chimpanzees, mangabey monkeys, and nine-banded armadillos. The disease is termed a chronic granulomatous disease, similar to tuberculosis, because it produces inflammatory nodules (granulomas) in the skin and peripheral nerves over time.
What causes leprosy?
Leprosy is caused mainly by Mycobacterium leprae, a rod-shaped slow-growing bacillus that is an obligate intracellular (only grows inside of certain human and animal cells) bacterium. M. leprae is termed an “acid fast” bacterium because of its chemical characteristics. When medical professionals use special stains for microscopic analysis, it stains red on a blue background due to mycolic acid content in its cell walls. The Ziehl-Neelsen stain is an example of the special staining techniques used to view the acid-fast organisms under the microscope.
What are leprosy early symptoms and signs?
Unfortunately, the early signs and symptoms of leprosy are very subtle and occur slowly (usually over years). The symptoms are similar to those that may occur with syphilis, tetanus, and leptospirosis. The following are the major signs and symptoms of leprosy:
Numbness (among the first symptoms)
Loss of temperature sensation (among the first symptoms)
Touch sensation reduced (among the first symptoms)
Pins and needles sensations (among the first symptoms)
Deep pressure sensations are decreased or lost
Blisters and/or rashes
Ulcers, relatively painless
Skin lesions of hypopigmented macules (flat, pale areas of skin that lost color)
Eye damage (dryness, reduced blinking)
Large ulcerations (later symptoms and signs)
Hair loss (for example, loss of eyebrows)
Loss of digits (later symptoms and signs)
Facial disfigurement (for example, loss of nose) (later symptoms and signs)
Source : https://www.medicinenet.com/leprosy/article.htm