Leprosy
Alternative names
Hansen's disease
Definition
An infectious disease, known
since Biblical times, which is characterized by
disfiguring skin lesions, peripheral nerve
damage, and progressive debilitation.
Causes
and risks
Leprosy is caused by the
organism Mycobacterium leprae. It is
a difficult disease to transmit and has a long
incubation period, which makes it difficult to
determine where or when the disease was contracted.
Children are more susceptible than adults to contracting
the disease.
Leprosy has two common forms, tuberculoid and
lepromatous, and these have been further subdivided.
Both forms produce lesions on the skin, but the
lepromatous form is most severe, producing large
disfiguring nodules. All forms of the disease
eventually cause peripheral neurological damage
(nerve damage in the extremities) manifested by
sensory loss in the skin and weakness of the muscles.
People with long-term leprosy may lose the use
of their hands or feet due to repeated injury
which results from absent sensation.
Leprosy is common in many countries in the world,
and in temperate, tropical, and subtropical climates.
Approximately 100 cases per year are diagnosed
in the United States. Most cases are limited to
the South, California, Hawaii, and U.S. island
possessions. Effective medications exist, and
isolation of victims in "leper colonies" is unnecessary.
The emergence of drug-resistant Mycobacterium
leprae, as well as increased numbers
of cases worldwide, have led to global concern about
this disease.
Prevention
Prevention consists of avoiding
close physical contact with untreated people.
People on long-term medication become noninfectious
(they do not transmit the organism that causes
the disease).
Symptoms
History of:
- exposure or family members with leprosy
- living or visiting areas of the world where
leprosy is endemic (cases are known to occur
in that area)
Symptoms include:
- one or more hypopigmented skin lesions that
have decreased sensation to touch, heat, or
pain
- skin lesions that do not heal after several
weeks to months
- numbness or absent sensation in the hands
and arms, or feet and legs
- muscle weakness resulting in signs such
as foot drop (the toe drags when the foot
is lifted to take a step)
Signs
and tests
- Lepromin skin test can be used to distinguish
lepromatous from tuberculoid leprosy, but
is not used for diagnosis.
- Skin scraping examination for acid fast bacteria
(typical appearance of Mycobacterium leprae)
Treatment
Medications used to eliminate
the microorganism and to reduce symptoms include:
- Dapsone
- Rifampin
- Clofazimine
- Ethionamide
- Aspirin, prednisone, or thalidomide are
used for the control of inflammation (e.g.,
"erythema nodosum leprosum") that may occur
with therapy
Prognosis
Early recognition is important.
Early treatment limits damage by the disease,
renders the person noninfectious, and allows for
a normal lifestyle.
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