What is Hansen’s disease (leprosy)?
Hansen’s disease (leprosy) is a chronic bacterial
disease caused by Mycobacterium leprae. Leprosy is
characterized by the involvement primarily of skin
as well as peripheral nerves and the mucosa (lining)
of the upper airway.
There are four major forms of
the disease:
- Tuberculoid: one or a few well-demarcated,
hypopigmented, and anesthetic (without feeling)
skin lesions, frequently with active, spreading
edges and a clearing center; peripheral nerve
swelling or thickening also may occur
- Lepromatous: a number of reddened bumps that
may occur on the face, hands and feet with skin
lesions in a bilateral and symmetrical distribution that progress to thickening of the skin
- Borderline (dimorphous): skin lesions
characteristic of both the tuberculoid and
lepromatous forms
- Indeterminate: early lesions, usually
hypopigmented bumps, without developed
tuberculoid or lepromatous features
Who gets Hansen’s disease?
Anyone can get Hansen’s disease if they become
infected with M. leprae. Most people who become
infected have had prolonged contact with someone else who already has leprosy.
Leprosy is very rare in the United States, but is common in other parts of the world. Places where
leprosy is common include South and Southeast Asia
and some parts of Latin America.
How is Hansen’s disease spread?
The exact mode of transmission for leprosy has
never been determined but prolonged contact with
an infected person appears to be necessary for transmission.
What are the symptoms of Hansen’s disease?
People with Hansen’s disease develop the
characteristic skin lesions and have decreased
sensation in the area where the skin lesions have
developed.
How soon after exposure do symptoms
appear?
This is variable and can range from nine months to 20
years.
How is Hansen’s disease diagnosed?
The laboratory criteria for diagnosis include:
- Demonstration of acid-fast bacilli in skin or dermal
nerve, obtained from the full thickness biopsy of a lepromatous lesion.
- A case of Hansen’s disease (leprosy) is confirmed
when a clinically compatible case is also laboratory
confirmed.
What is the treatment for Hansen’s disease?
Doctors can prescribe antibiotics for leprosy.
How can Hansen’s disease be prevented?
Hansen’s disease is extremely rare in the United
States. It is also very slow to develop and can be
treated successfully with antibiotics.
In parts of the
world where leprosy is common, the best way to
prevent more people from getting leprosy is to
promptly recognize and treat those individuals who
are already afflicted.
Where can I get more information?
Contact your doctor, the Southern Nevada Health District, Office of Epidemiology at (702) 759-1300 or
the Centers for Disease Control and Prevention.
Case
definitions for infectious conditions under public health
surveillance. MMWR 1997; 46 (No. RR-10):15-16.