This document summarizes leprosy (Hansen's disease), caused by Mycobacterium leprae. It has an incubation period of 2-20 years and primarily affects the nerves, skin, eyes, and respiratory tract. Transmission occurs through direct contact with untreated patients or infected soil. Leprosy is classified into tuberculoid, lepromatous, borderline, and indeterminate forms based on symptoms and immune response. Tuberculoid leprosy causes localized skin lesions and nerve damage, while lepromatous leprosy results in widespread skin nodules and organ involvement. Diagnosis involves skin smears and biopsies examined microscopically. Treatment consists of multid

1. LEPROSY

2.  It is a non fatal slowly progressive chronic
granulomatous infection
 Causetive organism : Mycobacterium
leprae
 Incubation period : 2- 20 years
 Organs that infected : Nerves (nerve
schawann cells)
 Bacteria also invades either dermal nerve
or main peripheral nerve
 Cooler parts of the body is mainly affected
such as skin,mouth,eyes,peripheral
nerves,superficial lymph nodes and testes

3. MODE OF TRANSMISSION
 Direct contact with untreated leprosy patient
who shed numerous bacilli from damaged
skin,nasal secretion and from mouth
 Nasal droplet infection
 Infected soil
 Mother to infants by milk
 Materno –fetal transmission across the
placenta

4. ETIOLOGY
 Mycobacterium leprae – intracellular
parasite
 The organism is acid fast and
indistiguishable from other mycobacterium
 Detected in tissue sections by a modified
stain

5. CLASSIFICATION OF LEPROSY
 Tuberculoid leprosy (high resistance)
 Lepromatous leprosy (low resistance)
 Borderline leprosy
 Indeterminate leprosy

6. TUBERCULOID LEPROSY
 ORGAN INFECTED –Skin,PNS
 T.Leprosy patient have asymmetric enlargement
of one or few peripheral nerves
 Mainly affected – Posterior auricular,peroneal
and posterior tibial nerves,with associated
hypoesthesia and myopathy

7. PATHOPHYSIOLOGY
T – cell reach the perineurium
Destruction of Schwann cells
Fibrosis of epineuria
Epithelial granuloma
Necrosis

8. LEPROMATUS LEPROSY
 ORGANS INFECTED:Skin nodules, raised
plaques,or diffuse dermal infiltration on
face results in leonine facies
 SYMPTOMS : Loss of eyebrows and
eyelashes,dry skin

9. L leprosy bacilli attack
skin, PNS
invade schwann cells
axonal degeneration
bacilli
circulation all organ

10. BORDERLINE LEPROSY
 Shows all characteristics of tuberculoid and
lepromatous
INTERMEDIATE LEPROSY
 No specific dermatitis may be made

11. Pathogenesis
1st Stage:
Bacilli enter
skin or nasal mucosa
skin sensation delay
small patches developed

12. 2nd Stage ( secondary stage)
bacteria invade
multiply in nerve fibre
skin becomes thick and wrinkled and ear
become swollen
nodules formed at skin and nose
nodules discharge fluid

13. 3rd Stage:
bacteria burst out of nerve cells
peripheral tissues
proliferate deformities of hand

14. DIAGNOSIS
Leprosy in most commonly presents with both
characteristic skin lesion and skin
histopathology
 Lipromen skin test: Skin smears by splitting
the skin. Scrapping from the cut edges of
dermis and nasal smears
1. Acid fast staining (Ziehl-Neelsen) staining
2. Fite- Faraco staining
3. Gamori methenamine silver staining

15. TREATMENT
 Antimicrobial therapy
 Dapsone (50-100 mg/dl)
MOA:Inhibits the synthesis of dihydrofolic acid
through competition with para-amino-
benzoate for the active site of
dihydropteroate synthetase
 Clofazimine (50-100 mg/dl)- 3 times weekly
MOA: Inhibits mycobacterial growth and binds
preferentially to mycobacterial DNA

16.  Rifampine (600mg daily or monthly)
MOA: Inhibits bacterial RNA polymerase, the
enzyme responsible for DNA transcription
 Bacillus Calmette–Guérin (BCG) vaccine