Leprosy

• Alternative Names

  Hansen's disease

• Causes, incidence, and risk factors

  Leprosy is caused by the organism Mycobacteriumleprae. 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 lumps and bumps ( nodules).

  All forms of the disease eventually cause 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.

  Leprosy is common in many countries worldwide, 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, has led to global concern about this disease.

• Symptoms

  Symptoms include:

  • Skin lesions that are lighter than your normal skin color
    • 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
• Signs and tests
  • Lepromin skin test can be used to distinguish lepromatous from tuberculoid leprosy, but is not used for diagnosis
  • Skin lesion biopsy
  • Skin scraping examination for acid fast bacteria
• Treatment

  A number of different antibiotics are used to kill the bacteria that cause the disease.

  Aspirin, prednisone, or thalidomide are used to control inflammation.

• Expectations (prognosis)

  Early recognition is important. Early treatment limits damage by the disease, renders the person noninfectious (you can't catch the disease from them), and allows for a normal lifestyle.

• Complications
  • Cosmetic disfigurement
  • Permanent nerve damage
• Calling your health care provider

  Call your health care provider if you have symptoms of leprosy, especially if you've had contact with someone who has the disease. Cases of leprosy in the United States need to be reported to the Centers for Disease Control and Prevention.

• 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).

• References

  Ernst JD. Leprosy (Hansen's disease). In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier. 2007: chap 347.

  Kumar B, Dogra S. Leprosy. In: Rakel RE, Bope ET, eds. Conn's Current Therapy 2008. 60th ed. Philadelphia, Pa: Saunders Elsevier; 2008: chap 25.

Review Date: 8/28/2009

Reviewed By: Linda Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.