Guidelines
Leprosy

Leprosy

Background

  • A chronic infectious disease caused by Mycobacterium leprae - an acid-fast bacillus.
  • It mainly affects the skin, peripheral nerves and mucous membranes. It is transmitted from one person to another via the respiratory tract (possibly, very rarely, through broken skin).

  • It is classified into paucibacillary (PB) or Multibacillary (MB) Leprosy.

  • One or more hypopigmented (pale) skin patches with definite loss of sensation
  • There may be skin nodules or smooth, shiny diffuse thickening of the skin without loss of sensation
  • Damage to peripheral nerves: thickened nerve, loss of function and weakness of muscles supplied by affected nerves
  • Tuberculoid or Paucibacillary (PB) leprosy: 1-5 patches
  • Lepromatous or Multibacillary (MB) Leprosy: More than 5 patches
  • Hypopigmentation e.g. birthmark, early vitiligo
  • Fungal infections of the skin
  • Other nodular conditions, e.g. Kaposi’s sarcoma, neurofibromatosis, secondary syphilis
  • Other causes of peripheral nerve damage, e.g. diabetes mellitus
  • Psoriasis, molluscum contagiosum
  • In most cases, a definite diagnosis of leprosy can be made using clinical signs alone
  • At referral centre: stain slit skin smears for Acid Fast Bacilli (AFB)
  • Skin biopsies NOT recommended as a routine procedure

Cause

Mycobacterium leprae

Management