Leprosy, also known as Hansen’s disease, is a chronic bacterial infection that primarily affects the skin, nerves, and mucous membranes of the respiratory tract. It causes skin ulcers, nerve damage, and muscle weakness. The cooler areas of the body—such as the eyes, nose, earlobes, hands, feet, and testicles—are the most commonly affected.

Leprosy is considered a relatively rare disease, with an estimated 208,000 cases worldwide. The incubation period for leprosy ranges from 6 months to 20 years, with symptoms typically appearing 3 to 5 years after infection.

Types of Leprosy

Leprosy is classified into three types, based on the immune response of the patient:

1.     Tuberculoid Leprosy: This type has a strong immune response, and symptoms are mild. It usually presents with a single patch or a few skin patches and numbness in specific areas. This form is considered mild and only mildly contagious.

2.     Lepromatous Leprosy: In this type, the immune response is weak. It is the most severe and contagious form. Symptoms include widespread skin patches, skin lesions and nodules, muscle weakness, and involvement of the genitals, kidneys, and nose. It may also cause hair loss.

Causes of Leprosy

Leprosy is primarily caused by the Mycobacterium leprae bacterium, which spreads from person to person through contact with nasal or respiratory droplets from an infected individual, especially through sneezing or coughing. Risk factors include:

-         Frequent contact with an infected person, which increases the risk significantly.

-         Genetic predisposition—if one or both parents had leprosy, there may be a higher risk, although the disease itself is not inherited.

-         Entry of the bacteria through skin abrasions, wounds, or via the nasal lining during exposure to respiratory droplets.

-         Exposure to certain infected animals, such as monkeys, chimpanzees, or armadillos—though this mode of transmission is rare.

Symptoms of Leprosy

Leprosy primarily targets the skin and peripheral nerves outside the brain and spinal cord, and can affect the eyes and soft tissue inside the nose. The main symptoms include chronic skin ulcers, deformities, and nodules that may take weeks or months to heal.

Common symptoms include:

-         Numbness and tingling

-         Loss of sensation, especially in the arms and legs

-         Inability to feel pain

-         Inability to sense temperature

-         Muscle weakness and joint pain

-         Nerve damage

-         Weight loss

-         Skin rashes

-         Painless skin ulcers

-         Pale patches of skin resembling vitiligo, often with numbness in the affected area

-         Dry eyes and reduced eyelid movement

-         Loss of fingers

-         Hair loss, including eyebrows

-         Facial disfigurement

Prevention of Leprosy

Most people have a natural immunity to leprosy, but you can reduce your risk by following these recommendations:

-         Avoid touching nasal secretions or ulcers when in contact with an infected person

-         Encourage treatment compliance, as patients under proper treatment are not contagious

-         Consult a doctor regarding the use of antibiotics as a preventive measure

Although there is no specific vaccine for leprosy, studies show that the BCG vaccine (used for tuberculosis) offers more than 50% protection against leprosy.