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Quick Facts


(Hansen Disease; Hansen's Disease)


The Manual's Editorial Staff

Last full review/revision Oct 2020| Content last modified Oct 2020
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What is leprosy?

Leprosy is an infection caused by bacteria called Mycobacterium leprae.

  • Most cases of leprosy happen in India, Brazil, and Indonesia

  • Symptoms usually start slowly 5 to 7 years after infection

  • The disease damages mainly your nerves and skin

  • People are often afraid of leprosy because it causes visible, permanent body damage if it isn't treated

  • However, leprosy doesn’t spread easily from person to person, isn't life-threatening, and is treatable with antibiotics

What causes leprosy?

Leprosy is caused by the bacteria Mycobacterium leprae. The bacteria is spread by long-term contact with people who have leprosy. You don't get leprosy just by casually touching or passing near somebody with the disease. Also, armadillos can carry leprosy. Some people get it from contact with armadillos.

Most people who are infected don't get any symptoms because their immune system fights off the infection. Leprosy symptoms develop if the immune system is weak. Some people have genes that make them more likely to get leprosy.

Most cases of leprosy happen in India, Brazil, and Indonesia. In the United States, most people with leprosy come from countries with high rates of the infection.

What are the symptoms of leprosy?

Symptoms start slowly. At first you may have:

  • Bumps and rashes on your skin—the rash doesn’t itch

  • Numbness around the rash

Later, more severe symptoms include:

  • Skin bumps that swell, become red and painful, and open into sores

  • A loss of the sense of touch in your fingers—you have trouble feeling pain or hot and cold

  • Muscle weakness—this can cause your fingers to curl or your foot to become too weak to bend

  • Sores on the bottom of your feet

  • Stuffy nose

  • Loss of vision or blindness

  • Fever

How do doctors tell if I have leprosy?

Doctors will take a sample of your skin and look at it under a microscope.

How do doctors treat leprosy?

Doctors will:

  • Have you take 2 or 3 antibiotics for 6 to 24 months depending on your symptoms

People with a weak immune system may need to take antibiotics for a longer time.

Antibiotics can stop leprosy from getting worse, but they can’t cure nerve damage that's already happened. For this reason it’s important to start treatment early.

How can I prevent leprosy?

To lower your chance of getting leprosy:

  • Don’t touch the body fluids or rash on an infected person

  • Don’t touch armadillos

After people with leprosy start taking antibiotics, they can't transmit the disease. But doctors keep an eye on people in their household to see if they start having any symptoms of leprosy.

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