pathophysilogy II PHARM-D

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