Leprosy is a progressive bacterial infection caused by Mycobacterium leprae. It is also known as Hansen’s disease. It primarily affects the peripheral nervous system, the lining of the nose, and the upper respiratory tract. This disease develops slowly and results in skin sores, muscle weakness, and nerve damage. If the disease is left untreated, it may cause severe disfigurement of skin and significant disability.
Types of Leprosy
Ridley-Jopling classified leprosy based on the type and affected area. It is classified into six types based on the severity of symptoms. They are:
- Tuberculoid Leprosy: It is a mild, less severe form of leprosy. It is characterized by one or few patches of flat, pale-colored skin and numbness. It is less contagious than other forms of leprosy.
- Lepromatous Leprosy: It is the most severe form of leprosy. It is more contagious and may affect the nose, kidneys, and reproductive organs. It is characterized by multiple bumps, numbness, muscle weakness, and rashes on the skin.
- Borderline Lepromatous Leprosy: It is a skin condition with numerous and symmetrical skin lesions. It is characterized by flat lesions, raised bumps, plaques, and nodules. Occasionally, it may become numb and persist.
- Mid-Borderline Leprosy: It is most common and unstable form of leprosy. It resembles tuberculoid leprosy, but the symptoms are irregular and numerous. Limb and peripheral nerves are affected by large patches of skin lesions, thereby leading to loss of sensation.
- Intermediate Leprosy: This type is characterized by few flat lesions that heal by themselves or may progress to more severe type.
- Borderline Tuberculoid Leprosy: The lesions are similar to tuberculoid leprosy but are smaller and numerous. This type of leprosy may persist or advance to another form of leprosy.
World Health Organization(WHO) has classified leprosy based on the number of skin lesions. Types of leprosy as per WHO are as follows:
- Paucibacillary Leprosy: Skin lesions with no bacilli are seen in a skin smear.
- Multibacillary Leprosy: Skin lesions with bacilli are seen in a skin smear.
Signs and Symptoms
Usually, the symptoms of leprosy take 3-5 years to appear. Rarely, the symptoms do not develop until 20 years of age. The signs and symptoms are:
- Muscle weakness
- Numbness in the arms and legs
- Skin lesions
- Nerve injury
- Ulcers, relatively painless
- Facial disfigurement
Leprosy is a contagious disease mainly caused by a slow-growing bacterium called Mycobacterium leprae. These bacteria grow extremely slow. Leprosy can spread by oral or nasal secretions of the affected person. The routes of transmission are still being researched for leprosy. Children are more susceptible to get leprosy than adults. This disease has an incubation period of 5 years.
Delayed diagnosis and treatment of leprosy can lead to serious complications such as:
- Kidney failure
- Iritis (an inflammation of eye)
- Hair loss
- Muscle weakness
- Chronic nasal congestion
- Permanent nerve damage
- Erectile dysfunction and infertility in men
A doctor conducts a physical examination to look for telltale signs and symptoms of the disease. The doctor may conduct the following diagnostic tests to diagnose leprosy in detail:
- Lepromin Test: This test is used to determine the type of leprosy in a patient. It is also called as leprosy skin test. In this test, a standardized extract of inactivated “leprosy bacillus” is injected into the skin, typically on the forearm. People with tuberculoid or borderline tuberculoid leprosy experience irritation at the site of injection. However, this test is not recommended as a primary mode of diagnosis.
- Skin Smear Test or Skin Biopsy Test: A sample of affected skin is collected and stained with M. leprae to check if the cell growth has a rash or if it is cancerous.
The World Health Organization has developed a multidrug therapy to cure all the types of leprosy. Early treatment may prevent skin damage, nerve damage, disease spread and other serious complications associated with leprosy. Treatment depends on the type of leprosy.
- Antibiotics: Antibiotics are prescribed to treat the infection associated with leprosy. Long-term treatment with antibiotics is recommended for six months to a year. Individuals with severe leprosy may need to take antibiotics for a longer time. These antibiotics cannot treat nerve damage.
- Anti-inflammatory drugs: Anti-inflammatory drugs may include steroids such as prednisone. These drugs are used to treat nerve pain and damage related leprosy.
- Thalidomide: Thalidomide is a potent immuno-suppressant drug and helps to treat skin nodules. Thalidomide is known to cause severe and life-threatening birth defects. Thus, thalidomide should not be taken by women who are pregnant or who may become pregnant.
The best way to prevent leprosy is to avoid long-term physical contact with the affected person.