Leprosy

Summary

• Leprosy is an infectious disease that has been known since biblical times.
• It is characterised by disfiguring skin sores, nerve damage, and progressive debilitation.
• Contrary to popular belief, leprosy is not very contagious.
• Leprosy causes nerve damage which causes sensory loss in the affected skin.
• Early treatment limits damage by the disease, renders the person non-infectious, and allows for a normal lifestyle.

Alternative names

Hansen's disease

What is leprosy?

Leprosy is an infectious disease that has been known since biblical times. It is characterized by disfiguring skin sores, nerve damage, and progressive debilitation.

What causes leprosy?

Leprosy is caused by the organism Mycobacterium leprae. It is not very contagious (difficult to transmit) and has a long incubation period (time before symptoms appear), 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 sores on the skin, but the lepromatous form is most severe, producing large, disfiguring nodules (lumps and bumps).

All forms of the disease eventually cause peripheral neurological damage (nerve damage in the arms and legs) which causes sensory loss in the skin and muscle weakness. People with long-term leprosy may lose the use of their hands or feet due to repeated injury resulting from lack of sensation.

What are the symptoms of leprosy?

Symptoms include:

• Skin lesions that are lighter than your normal skin colour
  • Lesions have decreased sensation to touch, heat, or pain
  • Lesions do not heal after several weeks to months
• Numbness or absent sensation in the hands, arms, feet, and legs
• Muscle weakness

How is leprosy diagnosed?

Leprosy can be detected with the following 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

How is leprosy treated?

• A number of different antibiotics are used to kill the bacteria that cause the disease.
• Aspirin, prednisone, or thalidomide are used to control inflammation.

What is the prognosis?

Early recognition is important. Early treatment limits damage by the disease, renders the person non-infectious, and allows for a normal lifestyle.

Permanent nerve damage and cosmetic disfigurement are possible complications.

When to call your doctor?

Call your health care provider if signs or symptoms described here occur, especially following exposure.

How can leprosy be prevented?

Prevention consists of avoiding close physical contact with untreated people. People on long-term medication become non-infectious (they do not transmit the organism that causes the disease).

(Health24, January 2009)