Mycobacterium Leprae

Question 1

➢Disease caused of leprae

Answer 1

● Tuberculoid leprosy.

● Lepromatous leprosy.

Question 2

Presentation of Tuberculoid leprosy

Answer 2

● Hypopigmentation.

● Unilateral macules (not raised).not disseminated

potent cell mediated immunity

Question 3

Presentation of Lepromatous leprosy

Answer 3

● Bilateral nodules (raised)

weak cell mediated immunity

● Leonine face:

skin anaesthesia, Resorption of bones, Bacteria causes infiltration of the skin

● Erythema Nodosum Leprosum (ENL):
painful nodules
دي بتجي بعد ما الزول يتعالج ومناعته تقوى

Question 4

➢Transmission of leprae

Answer 4

prolonged contact with infected patients.

Question 5

➢Pathogenesis if leprae

Answer 5

Tropism (affinity) of the bactera:

● To skin histiocytes (damage the skin).

● Endothelial cells.

● Schwann cells (damage the nerves).

The damage has 2 causes:

● Direct contact with bacteria. (In lepromatous leprosy)

● By CMI attack on nerves . (In tuberculoid leprosy)

Question 6

lepromin skin test. In TL and LL

Answer 6

TL +ve
LL-ve

Question 7

➢Complications of lepromatous leprosy

Answer 7

● Auto-amputation of nose and fingers (due to bone resorption).

● Osteomyelitis

Question 8

➢Diagnosis of M leprae

Answer 8

1. Specimen collection:

From the site of infection:

● Nerve biopsy or skin scraping.

2. Microscopy: By acid-fast stain.

● In Tuberculous Leprosy:

• No organism is seen (because of increased CMI)
• Granuloma is found

● In Lepromatous Leprosy:

• Many acid-fast bacilli are seen (because of decreased CMI)
• Lipid-laden macrophages (foam cells) are found

3. Culture:

Not cultured usually. (We can culture it in armadillos).

147 4. PCR.

➢Treatment:

● Tuberculoid Leprosy: Dapsone + Rifampicin.

● Lepromatous Leprosy: Dapsone + Rifampicin + Clofazimine.

● ENL: Thalidomide.عنده اعراض جانيك ما يندبه للحوامل غايتو

➢Prevention:

● There is no vaccine.

● Chemoprophylaxis: Dapsone