presenter - SANA ARMAN

HISTORY:

Leprosy or Hansens disease.Discovered in 1873 by G.H Armauer Hansen.

CARDINAL SIGNS• Numbness : hands & feet

• Painful and/or tender nerves

• Burning sensation in the skin

• Painless swelling or lumps in the face and earlobes

• Loss of eyebrows and or eyelashes.

(a) Nodules on the face (b) skin patch on the face

(c) an enlarged nerve in the neck

LAB DIAGNOSISOVERVIEW :

1. Specimens

2. Acid fast staining

3. Skin and nerve biopsy

4. Animal inoculation

5. Lepromin test

1. SPECIMENSNasal mucosa, skin lesions, ear

lobules. Skin and nerve biopsy.

Edges of the lesion.Slit and scrape

method:

• Pinch the site tight

• Incise

• Scrape & collect material

• Smear on a slide

SKIN:

SKIN BIOPSY:Active edges of the patches NERVE BIOPSY :From thickened nerves

2. ACID FAST STAINING Ziehl-Neelson method Decolourising agent = 5% sulphuric acid Lepra cells confirm the diagnosis

of lepromatous leprosy.

i. Bacteriological index (B.I) :

Number of total bacilli in a tissue.B.I is calculated by totalling the

grades and divided by no. of smears.Minimum of 4 skin lesions,a nasal

swab & both the ear lobes are to be examined.

Percentage of uniformly stained bacilli out of the total number of bacilli counted.

For assessing the progress of patients on chemotherapy.

ii. MORPHOLOGICAL INDEX(M.I) :

• For histological confirmation of tuberculoid bacilli ( as they cannot be demonstrated in direct smear)

• Skin biopsy is also useful in diagnosis and accurate classification of leprosy lesion.

3. SKIN AND NERVE BIOPSY

Obligate intracellular parasite. Lacks many necessary genes for

independent survival.

WHY CAN’T WE CULTIVATE Mycobacterium leprae

IN AN ARTIFICIAL CULTURE MEDIUM???

4. ANIMAL INOCULATION

Nine banded armadillo Injection of ground tissue from

lepromatous nodules or nasal scrapings from leprosy patient into the foot pad of mice.

Typical granuloma at the site of inoculation within 6 months.

5. LEPROMIN TEST• Delayed type of hypersensitive reaction.

• First described by Mitsuda in 1919.

• Lepromins used as antigens may be of human origin (lepromin H) or armadillo derived (lepromin A).

Procedure : Carried out by the intradermal

injection of 0.1 ml of lepromin.

1)Early reaction of Fernandez

2)Late reaction of Mitsuda

Biphasic response:

USES OF LEPROMIN TEST:a) Classification of leprosy:

- Positive in tuberculoid leprosy

- Negative in lepromatous leprosy

b) Assessment of prognosis:

- Positive lepromin test indicates a good prognosis.

- Negative lepromin test indicates a bad prognosis.

c) Assessment of resistance:- To assess the resistance of an individual to

leprosy.

- Resistance is indicated by positive lepromin test.