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What is Leprosy?

Leprosy is a bacterial infectious disease that can cause severe skin sores and damage nerves in the limbs. This effect of this chronic infection can lead to disfigurement, discolouration, deformities, and lumps on  the skin.

The outbreak of this disease can be seen on all continents. In ancient times, leprosy had been known as a contagious disease. However, in modern medical science, leprosy is not considered contagious. It only spreads if a person gets in contact with the nose and mouth droplets of a leprosy patient regularly.

This disease majorly affects skin, eyes, peripheral nerves, and upper respiratory tract with visible leprosy symptoms. Also, in most cases, the leprosy disease transmits through respiratory routes. Nonetheless, insects can not transmit leprosy.

Leprosy Causes

Leprosy is caused by bacteria called mycobacterium leprae that grows slowly with time. Another name of this infectious disease is Hansen’s disease. This name was given after scientist Dr Gerhard Henrik Armauer Hansen, the discoverer of the bacteria -M. leprae.

Types of Leprosy

Depending on the severity of signs and symptoms, leprosy can be classified into six categories. 

  1. Intermediate Leprosy 

Intermediate leprosy is the first stage of leprosy. During this early stage, the flat lesion is the symptom, and it does not show any progression if the patient has strong immunity.

  1. Tuberculoid Leprosy

This is a less severe and mild kind of leprosy. Tuberculoid leprosy shows patches of pale-coloured and flat skin with no sensation on it. Due to the nerve damage, patients cannot feel any sensation on the affected parts of their bodies. This infection can be healed by itself or also progressed to the next stage.

  1. Borderline Tuberculoid Leprosy

This infection has almost similar symptoms as the tuberculoid stage. However, the number of infections can be more, which can progress to tuberculoid or other advanced stages.

  1. Mid-Borderline Leprosy

The symptoms are similar to the previous version of leprosy with numbness and reddish plaque. This infection can progress as well as regress to another stage.

  1. Borderline Leprosy

This is mostly a cutaneous skin condition that includes several wounds with plaque, bumps, etc. that can advance or regress.

  1. Lepromatous Leprosy

It is the most infectious and severe type of leprosy among all with multiple lesions. The affected body parts can have numbness, bumps, rashes, and muscle weakness. Severe symptoms can include hair loss, limb weakness, and body parts like the male reproductive system, kidney and nose can get affected. Moreover, this type of leprosy never regresses. 


1. Leprosy is Caused By Which Bacteria?

Ans. The bacteria called mycobacterium leprae is the reason for leprosy.

2. How Many Types of Leprosy are There?

Ans. Six types of leprosy are there – 

  • Intermediate

  • Tuberculoid

  • Borderline tuberculoid

  • Mid-borderline

  • Borderline

  • Lepromatous

Signs and Symptoms of Leprosy

The initial signs of leprosy appear on the skin, and then these gradually move towards peripheral nerves situated on the outside of the brain and spinal cord. The period between symptoms appearance and being exposed is termed as the incubation period. 

Doctors find it difficult to diagnose if this period increases. 

Here are Some Leprosy Symptoms -

  • Bleeding from nose

  • Growth or bumps on the skin

  • Enlargement of nerves.

  • Severe pain.

  • Visible ulcers on feet sole.

  • Dry, stiff, and thick skin.

  • Paralysis and muscle weakness.

  • Numbness on different body parts like arms, hands, legs, and feet.

  • Lesions without any sensation on them.

  • Vision problems that can even lead to blindness.

Diagnosis and Treatment of Leprosy

Depending on leprosy symptoms, this disease is diagnosed by skin test or biopsy of the lesion. Based on the type of infection, the treatment process is chosen.

Doctors prescribe one or multiple antibiotics for a long-time to treat leprosy. Sometimes the medicine can last more than one year. However, antibiotics can only treat bacteria. Thus, to reduce the nerve pain, doctors recommend some anti-inflammatory drugs.

For further references on leprosy symptoms, download our Vedantu app which offers convenient access to our detailed study materials and online interactive sessions.

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FAQs on Leprosy

1. What is the Definition of Leprosy?

Ans. It is a bacterial infectious disease that initially affects skin with wounds and later progresses to the peripheral nerve.

2. What Causes Leprosy?

Ans. A bacteria called mycobacterium leprae causes leprosy.

3. How is Leprosy Treated?

Ans. Leprosy, a bacterial disease, is treated with the help of antibiotics. Notably, it takes a long time to cure an individual of leprosy.

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