Leprosy

Definition

• Chronic granulomatous infection of skin & peripheral nerves
• Infection by Mycobacterium leprae

Epidemiology

• Endemic in some tropical regions
• Commonest cause of peripheral neuropathy worldwide

Microscopy

• Acid-Fast bacilli (AFB)
  • Carbol-Fuscin stain » Red
• Fastidious
  • Unable to be grown on artificial media

Pathology

• Virchow Cells
  • Vacuolated macrophages
• Granuloma

Clinical Findings

• Insidious onset
• Involves
  • Skin
  • Superficial nerves
  • Nose, pharynx & larynx
  • Eyes
  • Testicles
• Skin lesions are
  • Pale anaesthetic macule 1-10cm ø
  • Diffuse erythematous nodules 1-5cm ø
  • Diffuse skin infiltration
• Neurological disturbances are
  • Nerve infiltration & thickening
  • Resultant
    • Anaesthesia & parasthesiae
      • Trophic ulcers
    • Bone resorption
      • Short digits
    • Other
      • Leonine (lion-like) Facies
• Two Forms Described
  • Lepromatous Type
    • Progressive malignant course
    • Characterized by severely impaired cell-mediated immunity
    • Late symmetrical poly-neuropathy
  • Tuberculoid Type
    • Non-progressive benign course
    • Characterized by vigorous cell-mediated response
    • Anaesthetic skin patches
    • Thickened nerves

Diagnosis

• Bacilli seen in scrapings from skin or nasal mucosa
• Culture negative
• » Involve infectious diseases physicians

Management

• Sulphone & Rifampicin for ~ 2 years
• Prednisone for acute neurological function loss
• Deal with Charcot Joints