Doctor's Notes on Leprosy (Hansen's Disease)
Leprosy, also called Hansen's disease, is a chronic infectious disease that causes severe disfiguring sores on the skin, nerve damage in the peripheral nerves of the arms and legs, and damage to the mucosa of the upper respiratory tract and the eyes. Leprosy can permanently damage these structures, resulting in disfigurement and disability. Leprosy is a curable disease and in the year 2000, global elimination of leprosy was achieved.
Symptoms of leprosy vary depending on the individual's immune response and the number of skin lesions and nerve involvement and may include flat or raised skin lesions or nodules; single or multiple skin lesions that are often found on cooler parts of the body such as the face, buttocks, and extremities; thickening of the skin and peripheral nerves; skin ulcerations; loss of sensation in peripheral nerves; muscle weakness (for example, clawed hand deformities, contractures, and foot drop); hoarseness; sexual dysfunction or sterility in men when testicles are affected; eye pain, eye redness, inability to close the eyelids, corneal ulcers, and blindness; loss of eyebrows and eyelashes; and destruction of nasal cartilage.
Leprosy (Hansen's Disease) Symptoms
The signs and symptoms of leprosy can vary depending on the individual's immune response to M. leprae. The WHO classification system uses clinical manifestations (the number of skin lesions and nerve involvement) as well as skin smear results to distinguish between forms of the disease. The two major WHO classifications are paucibacillary (PB) leprosy and multibacillary (MB) leprosy. However, within the WHO's simplified classification there can be a fairly wide range of patient presentations.
- Paucibacillary leprosy
- Two to five skin lesions with negative skin smear results at all sites
- Paucibacillary single lesion leprosy
- One skin lesion with negative skin smear results
- Multibacillary leprosy
- More than five skin lesions with or without or positive skin smear results at any site
The Ridley-Jopling classification is another classification system that is used globally in evaluating patients in clinical studies and contains five different classifications of leprosy that further define the patient's severity of symptoms and disease progression. The six different categories, in order of increasing severity of disease, include indeterminate leprosy, tuberculoid leprosy, borderline tuberculoid leprosy, mid-borderline leprosy, borderline lepromatous leprosy, and lepromatous leprosy.
In general, the signs and symptoms of leprosy may vary with the form of the disease and include the following:
- Flat or raised skin lesions or nodules, often less pigmented than the surrounding skin, though they may appear reddish or copper colored
- Single or multiple skin lesions that are often found on cooler parts of the body such as the face, buttocks, and extremities
- Thickening of the skin and peripheral nerves
- Ulcerations of the skin
- Peripheral nerve involvement leading to loss of sensation
- Peripheral nerve involvement leading to muscle weakness (for example, clawed hand deformities, contractures, and foot drop)
- Testicular involvement leading to sexual dysfunction or sterility
- Eye involvement including eye pain, eye redness, inability to close the eyelids, corneal ulcers, and blindness
- Loss of eyebrows and eyelashes
- Destruction of the nasal cartilage
Leprosy (Hansen's Disease) Causes
Leprosy is an acquired infectious disease that can affect individuals of all ages. It is caused by the acid-fast, rod-shaped bacteria Mycobacterium leprae, which was discovered in 1873 by G.A. Hansen.
- Because the bacterium multiplies very slowly, the signs and symptoms of leprosy may not develop until much later after exposure to M. leprae (ranging from several weeks to 20 years or more).
- Though humans are the major reservoir and host for infection with M. leprae, other animals such as armadillos, chimpanzees, and mangabey monkeys, and macaques also serve as reservoirs of infection.
- Leprosy is thought to be transmitted via droplets from the nose and mouth during close prolonged contact with affected individuals, though the exact route of transmission has yet to be proven definitively.
- Not all individuals infected with M. leprae will go on to develop leprosy, because only 5%-10% of the population is thought to be susceptible to the infection for immunological reasons.
It's hard to believe, but the Black Death isn't just one for the history books or far-flung places. It's shown up recently in New Mexico, California, and Colorado, though it's still rare. Antibiotics can take care of it, but it can be life-threatening if it's not treated early enough. It's carried by rodents, like squirrels and mice, and the fleas that live on them.
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Bowel regularity means a bowel movement every day.See Answer
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.