Leprosy (Hansen's Disease): Nerve Damage, Transmission & Cure

Leprosy is a chronic infection caused by Mycobacterium leprae. It primarily targets skin and peripheral nerves.

Key Facts

• Transmission: Respiratory droplets; prolonged close contact. Low infectivity; >95% of people have natural immunity.
• Incubation: 3–5 years (range 1–20+).
• Cardinal signs: Hypopigmented/erythematous skin patches with sensory loss; thickened nerves; muscle weakness.
• Nerve damage: Leads to claw hand, foot drop, lagophthalmos (inability to close eye), anesthetic injuries → ulcers, amputations.

Diagnosis & Treatment

• Diagnosis: Clinical + skin smear (acid-fast bacilli) or PCR.
• MDT (Multi-Drug Therapy)—FREE worldwide via WHO:
  • Paucibacillary (≤5 lesions): Dapsone + Rifampicin × 6 months.
  • Multibacillary (>5 lesions): Dapsone + Rifampicin + Clofazimine × 12 months.
• Cure rates >95%; relapse rare. Nerve damage may be permanent if treatment delayed.

Stigma & Elimination

Leprosy is curable and non-infectious on treatment. Global elimination (<1 case/10,000) achieved in most countries; pockets remain. Stigma reduction is key to early case-finding.