Leprosy is a chronic disease of the nervous system which affects the skin and nerves caused by a bacteria known as Mycobacterium Leprae The organism was discovered by Gerhard Armauer Hansen ID: 933876
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Slide1
LEPROSY
By Mwila B. C.
Slide2DEFINITION
Leprosy is a
chronic disease
of the nervous system which affects the skin and nerves caused by a bacteria known as
Mycobacterium Leprae
.
The organism was discovered by
Gerhard Armauer Hansen
in Norway
in
1873
making it the first bacterium to be identified as causing disease in man.
Slide3Characteristics of the organism.
It is a strongly acid-fast, rod-shaped organism with parallel sides and rounded ends.
In size and shape it closely resembles the Tubercle Bacillus.
Under the electron microscope the bacillus appears to have a great variety of forms.
Slide4Portal of entry of M.Leprae.
Not definitely known.
However the two portals of entry seriously considered are the
skin
and the
upper respiratory tract.
Age at onset
:
Mainly affects young adults in their most productive period of life.
However, it can occur in old age.
Slide5INCUBATION PERIOD
The minimum incubation period is as short as few weeks and maximum as long as up to 30 years.
However the average period of incubation is 3-5 years.
Mortality
: The disease is rarely an immediate cause of death.
Cure of disease:
With
multi drug therapy (MDT),
cure is possible upon completion of treatment.
Slide6TYPES OF LEPROSY.
LEPROMATOUS LEPROSY
.
This is a type of leprosy which is common in persons with
low
resistance.
Leprosy Bacilli are widely disseminated through out the skin, nerves and
reticulo
-endothelial system.
There may be bacillary invasion of the eyes, testes, bones and mucous membrane of the mouth, nose, pharynx, larynx and trachea.
Slide7Lepromatous leprosy cont..
Skin lesions
.
The lesions are multiple, small and symmetrically distributed.
They take the form of macules, infiltrations (plaques), papules and nodules, all of which may be present in the same patient at the same time once the disease has become established
.
Nerve involvement
.
Nerves do not show signs of damage as early as in the other types of leprosy. Nerve thickening may be there and tends to be bilateral and symmetrical.
Other tissues involved are nails of fingers and toes, mucous membranes, eyes, bones, reticulo-endothelial system, testes and kidneys.
Slide8Tuberculoid leprosy.
This is a type of Leprosy seen in persons with a good resistance and may be purely neural or combined neural and dermal.
The infection is never widespread but is localised to one area or to a few areas asymmetrically
.
Slide9Tuberculoid leprosy cont..
Affected nerves may be thickened, and may be associated with sensory and motor disturbances such as face (trigeminal nerve), neck (great auricular nerve), forearm (
antebrachial
cutaneous
nerve),
little
and ring finger (ulna nerve), hand (median nerve at the wrist) thigh (femoral
cutaneous
nerve), lower leg (common
peroneal
nerve), dorsum of foot (superficial
peroneal
nerve) and sole of foot (posterior
tibial
nerve).
Skin lesions take the form of macules or infiltrations.
Lesions are usually few, large and asymmetrical.
Slide10Borderline leprosy
This is a type of Leprosy seen in persons with a limited or variable resistance and usually presents with skin and nerve involvement.
Skin lesions are macular, infiltrated or both, the earliest lesions being macules which are erythromatous or hypo pigmented
.
Nerves are involved asymmetrically and show palpable thickening and impaired function.
Other tissues are not affected directly but indirectly.
Both sensory and motor nerves may be affected.
Slide11Indeterminate leprosy
This is an early phase in natural history of Leprosy.
At this stage the disease has not yet
been
determined.
It usually presents as a single
macule
with uncharacteristic histology and absence f bacilli.
Slide12Clinical manifestations
Mode of onset is variable.
An erythrematous or hypo pigmented patch with loss of sensation.
Sometimes there may be loss of sensation without skin patches.
There may be tenderness, tingling or thickening of a nerve, an area of anaesthesia with some change in appearance of skin insensitiveness to burning, tingling or numbness of extremities.
Slide13Definition of a case of Leprosy.
A case of Leprosy is a person having one or more of the following features, and who has yet to complete a full course of treatment:
Hypo pigmented or reddish skin lesion with definite loss of sensation.
Involvement of the peripheral nerves, as demonstrated by loss of sensation and weakness of the muscles of hands, feet or face.
Skin smear positive for acid-fast bacilli.
Slide14Diagnosis of leprosy
Mostly based on signs and
symptoms such as, skin
lesions, single or
multiple and may be
hypopigmented
.
Lesions
may be seen as macules, papules or nodules.
History may reveal sensory
loss
e.
Nerve damage, nerve thickening, weakness of muscles supplied by the affected nerve
.
Skin smear may be positive
Slide15TREATMENT.
Multi-drug Therapy (MDT) is used.
None of these drugs should be used as
monotherapy
.
1.
Rifampicin
.
This is the most effective drug against
M.leprae
.
Dose
: 600mg
monthly
2.Clofazimine
Dose:
200-300mg
monthly
3
.
Dapsone
Dose:
100mg daily
Multibacillary – duration 12 months.
Paucibacillary – duration 6 months.
Slide16Clinical classification.
Multibacillary
More than 5 lesions.
Distribution more asymmetrical.
Loss of sensation.
Many nerve trunks affected.
Paucibacillary
Up to 5 lesions.
Hypo pigmented or
erythromatous
Asymmetrically distributed.
Definite loss of sensation.
Only one nerve trunk affected.
Slide17End of the lecture
Thank your for your attention
And may our good lord bless and protect you all
(Mwila b. c. 2009)