Leprosy - Causes, Symptoms, Diagnosis, Prevention & Treatment


Dr.R D Kharkar profile Authored by Dr.R D Kharkar on 2 Apr 2015 - 15:47.


Leprosy is a chronic infection caused by the bacteria called Mycobacterium leprae and Mycobacterium lepromatosis. It's one of the oldest diseases known to man and it is also called as Hansen's disease (HD). Its outbreak has affected and panicked people in every continent. It primarily affects the skin and peripheral nerves, but may also affect the eyes and the thin tissue inside the nose.


Tuberculoid: It is a less severe form of leprosy with only one or a few patches of flat, pale colored skin without sensation. It is less contagious than other types.

Lepromatous: It has widespread skin rashes and bumps with numbness and muscle weakness. It is comparatively more contagious than tuberculoid leprosy.

Borderline: It is a combination of both tuberculoid and lepromatous leprosy.




Leprosy is caused by mycobacterium leprae and mycobacterium leptospirosis (rod shaped, acid fast bacteria).It is believed to be transmitted from human to human through aerosol nasal secretions. It cannot be transmitted through physical contact as the bacteria involved in causing leprosy are not capable of crossing intact skin.

People living in countries where leprosy is endemic are at higher risk of developing the condition. These countries include certain parts of India, China, Egypt, Nepal and Japan. Genetic defects in immune system may also increase the risk.

Incubation period (time gap between bacterial contact and onset of symptoms) of Leprosy is very long, ranging from 3 to 20 years.

  • A discolored skin patch, with or without sensation may be the initial symptom.
  • Lumps or bumps on skin which remains for several weeks
  • Loss of feeling in the arms and legs due to nerve damage
  • Muscle weakness
  • Clawed hands
  • Ulcers on hands or feet

Diagnosis of leprosy is not confirmed by physical findings alone owing to a long incubation period of it. Certain laboratory tests like skin lesion biopsy and smear examination can be used to diagnose leprosy.

Skin lesion biopsy: A part of skin from the affected region is removed for determining the disease.

Skin smear examination: It is a test in which a sample of material is collected from a tiny cut in the skin and then stained for M. leprae.

Lepromin skin test: It is performed to determine the type of Leprosy. A small amount of leprosy-causing bacteria is injected into the skin on the upper forearm. People with tuberculoid or borderline tuberculoid leprosy will experience irritation at the site of injection.

Other tests:Liver function tests, creatinine test and nerve biopsy may be performed to help determine if other organs have been affected.


Leprosy should be treated properly and in time, to avoid the following complications:

  • Blindness/ Glaucoma
  • Disfiguration of the face
  • Erectile dysfunction and infertility in men
  • Kidney failure
  • Permanent damage to the nose, arms, legs and feet.

Leprosy is a curable disease and the WHO offers free treatment for patients suffering from leprosy.A fixed regimen is usually followed for treating leprosy with duration ranging from 6 months to 2 years based on the type and severity of the disease.

The goals of drug therapy are to eliminate the infection, to prevent complications, to halt its further transmission and to reduce morbidity.

Antibiotics: A number of different antibiotics can be used in the treatment. Combination of more than one drug is preferred over a single antibiotic to prevent bacterial resistance. The WHO recommends a multi-drug regimen comprising of Rifampicin, Dapsone and Clofazimine to treat Leprosy.

Anti-inflammatory drugs:These medications can help control swelling related to the disease. Ex: Aspirin, Prednisone, etc.

Thalidomide: It is a potent medication which suppresses the defense mechanism of our body. It can be used to treat skin nodules but it is rarely used due to its severe adverse reactions including birth defects.

Surgeries: Neural surgeries, eye procedures to restore eyelid function and cosmetic surgeries to construct facial look may be performed in advanced cases of the disease.

Leprosy patients should be monitored for the next 5-10 years post-completion of treatment to evaluate for signs of relapse.

Non-drug therapy:

  • Plenty of fluid intake can help expel the bacterial toxins from the body
  • Maintenance of hygiene is important to prevent further complications
  • Use of proper foot wear may prevent development of ulcers on foot
  • Drug compliance should be followed strictly to avoid relapse of the disease





  • Leprosy. Centre for Disease Control. Northern Territory Government, June 2013.
  • Leprosy. eMedicine. http://emedicine.medscape.com/





*Disclaimer This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.