Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae. It primarily affects the skin, peripheral nerves, mucous membranes, and sometimes the eyes. Despite its historical stigma, it is a curable disease, especially when diagnosed early.

Key Facts About Leprosy:

Cause: Mycobacterium leprae, a slow-growing bacterium.

Transmission: Likely spread through prolonged close contact with someone with untreated leprosy, often via respiratory droplets (like coughing or sneezing). It is not highly contagious.

Symptoms:

• Discolored skin patches (lighter or reddish, with loss of sensation)

• Numbness or tingling in hands and feet

• Muscle weakness

• Eye problems (if facial nerves are involved)

• Thickened nerves

Diagnosis: Clinical examination, skin smears, or biopsy.

Treatment:

• A combination of antibiotics (multi-drug therapy or MDT) for 6–12 months.

• MDT is provided free of charge by the World Health Organization (WHO).

Prognosis: Excellent with early treatment. Untreated cases can lead to permanent nerve damage, disability, and deformity.

Types of Leprosy (Clinical Classification):

• Tuberculoid: Milder form; few skin lesions; strong immune response.

• Lepromatous: More severe, widespread lesions; poor immune response.

• Borderline: Between the two, unstable form.

• WHO classifies for treatment purposes:

  • Paucibacillary (few bacteria, 1–5 skin lesions)

  • Multibacillary (many bacteria, more than 5 lesions

Common Misconceptions:

• Leprosy does not cause body parts to fall off; damage is due to nerve loss and subsequent injury.
• It is not highly contagious.
• People under treatment are not contagious.