Leprosy (Hansen’s Disease) Causes, Symptoms, Signs, Diagnosis With Treatment

Leprosy sd
Leprosy(Hansen’s Disease) types Causes of leprosy sign and Symptoms

Leprosy is a chronic infective disease, also called Hansen’s disease.

  • It is caused by Mycobacterium leprae.
  • Clinical manifestations are seen in skin, peripheral nervous system, upper respiratory tract, eyes, and testes.
  • The main involvement is of the peripheral nerve from large trunks to small dermal nerves.
  • The disease is transmitted from person to person.
M lepraetrg
Mycobacterium leprae M. lepra
M lepraeu
M. lepra


  • M. leprae is an obligate intracellular bacillus.
  • The bacteriologic index is a measure of infection with 4+ to 6+ denoting severe infection.
epidio leprocy
Epidemiology Mycobacterium leprae

Epidemiology Mycobacterium leprae:

  • It is a disease of the developing nations.
  • It is found in poor people, rural people and patients of AIDS.
  • Common in second and third decades. s more common in f1lllP.
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Transmission Epidemiology Mycobacterium lepra

Transmission  Mycobacterium leprae

  • Nasal droplet infection
  • Contact with infected soil
  • Aerosol – like a sneeze
  • Insect vectors
  • Dermal inoculation like tattoo
  • Intimate contact with infected person.
  • Caring for a leprosy patient by nurse and doctors does not give them infection.
Clinical features lfv
Clinical features Mycobacterium lepra
Clinical features l
Clinical features Mycobacterium lepra


Clinical features Mycobacterium lepra

  • · Incubation period 2 – years.
  • · The disease may be tuberculoid, borderline tu­berculoid, mid borderline, borderline lepromatous and lepromatous leprosy.
  • · This spectrum of presentation from tuberculoid to lepromatous is a change from asymmetric, localized macules and plaques to nodular, hard, symmetric and generalized skin lesions, an in­creasing bacterial load and decreasing immunity.



  • · Hypopigmented macules or plaques, sharply de­marcated, red, hypoesthetic, dry, scaly and an­hidrotic.
  • · A few peripheral nerves show asymmetric en­largement like the ulnar, posterior auricular, pero­neal, posterior tibial nerves.
  • · It is the most common form of disease.
  • · Lepromin skin test is positive.
Leprosy t



  • There are symmetrical skin nodules, raised plaques, leonine faeces.
  • Loss of eyebrows (specially lateral one-third), eye­lashes. ~ry scaly skin._
  • Leprabacilli are numerous on the skin and peripheral nerves.
  • Nerve enlargement and damage is  mmetrical. There is symmetrical peripheral neuropathy with nerve trunk enlargergment.
  • Upper respiratory tract, anterior chamber of eye and testes are involved .
  • Lepromin skin test is negative.


  • Leprosy may present with lepra reactions.
  • Lepra reactions may also occur after start of chemo­therapy.
Type 1 lepra reaction
Type 1 leprareaction

Type 1 lepra reaction —

  • It is common in borderline cases.
  • There are signs of inflammation over skin lesions. There is neuritis, low grade fever.
  • The ulnar nerve is very painful.
  • Nerve damage resulting in foot-drop may occur. Down grading reactions are lepra reactions before start of antimicrobial therapy.
  • Reversal reactions are leprareaction after start of therapy.
Type 2 Lepra reaction
Type 2Lepra reaction

Type 2 Lepra reaction —

  • It is also called erythema nodosum leproticum. It occurs within 2 years of start of therapy. There are painful red papules, malaise, high fever, neuritis, uvei­tis, lymphadenitis, orchitis, glomerulonephritis.
  • It may end in death.

LUCIO’S HENO ENON It is found in Mexico.

  • It is seen in diffuse lepromatous leprosy.
  • There are large ulcerated lesions on lower extremi­ties.
Complications of Leprosy Extremities
Complications ofLeprosyExtremities

Complications of Leprosy Extremities–
  • There is loss of fine touch, pain and heat sensation but position and vibration is spared.
  • There is clawing of hands due to ulnar and median nerve damage.
  • There is foot drop due to peroneal nerve palsy. There may be ulcers on the hands and feet.
  • Fingers and toes are lost due to osteolytic process and injury.


  • · Chronic nasal congestion
  • · Epistaxis
  • ·Destruction of nasal cartilage with saddle-nose deformity and anosmia


  • · Corneal insensitivity
  • · Uveitis
  • · Cataract
  • · Glaucoma
  • ·Blindness


  • · Orchitis
  • · Aspermia
  • · Impotence


  • · Secondary amyloidosis affecting liver and kid­ney



  • • Abscess
Diagnosis lepromatous leprosy Biopsyofskin


Diagnosis Biopsy of skin:

  • In lepromatous leprosy even normal skin will show the bacilli.
  • In tuberculoid leprosy biopsy must be taken from the lesion.
  • Scraping the skin and examining under the micro­scope may show the bacilli.


IgM antibodies

  • PGL 1 (phenolic glycolipid) are found in untreated patients.

Treatment lepromatous lepros

  • Tuberculoid leprosy – Dapsone 100 mg/day for 5 years.
  • Lepromatous leprosy – Rifampin 600 mg/day for 3 years + Dapsone 100 mg /day for a long time.
  • Treatment of reactions – Glucocorticoids ­Prednisone 40-60 mg/day gradually tapered and continued for 3 months.
  • Clofazimine 200 to 300 mg/d is less efficacious than steroids.

Treatment of ENL (erythema nodosum leprosum)

  • – Glucocorticoids.

Prevention lepromatous lepros

  • · Vaccination at birth with BCG.
  • · Dapsone reduces incidence of tuberculoid lep­rosy.


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