Written by Dr.Md.Redwanul Huq (Masum)

Sunday, 15 January 2012 16:12

Definition:

It is a type of chronic granulomatous infectious disease which is caused by Mycobacterium leprae involving skin, peripheral nerves, eye, upper respiratory tract and testes.

Classification of leprosy:

It can be classified as-

1. Tuberculoid leprosy
2. Bordenline tuberculoid leprosy
3. Borderline leprosy
4. Borderline lepromatous leprosy
5. Lepromatous leprosy.

Clinical features of Tuberculoid leprosy:

1) Skin lesion –

a) Hyposthetic hypopigmented macule
b) Shiny skin with sharp erythematous margin
c) Centre of the lesion becomes atrophied and depressed.

2) Nerve lesion –

In this type of leprosy the following nerves can be thickened and palpable-

a) Ulner nerve near the elbow joint
b) Radial nerve near the wrist joint
c) Median nerve above the elbow and wrist joints
d) Popliteal nerve in the popliteal fossa
e) Great auricular nerve over sternocleidomastoid muscle
f) Posterior tibial nerve near medial malleolus.

Clinical features of Lepromatous leprosy:

1) Skin lesion –

a) Formation of numerous non- anaesthetic erythematous macules symmetrically involving the body
b) The lesions have ill defined margins
c) In advanced stage of the disease – there are diffuse thickening of the face, the eye brows, ear lobules and there is loss of eye lashes resulting the appearance of “Lionine facies”.

2) Nerve lesion –

Not significant.

Cardinal features of leprosy:

• Anaesthetic skin lesions ( in tuberculoid leprosy)
• Thickening of peripheral nerves
• Skin smears or biopsy shows acid-fast bacilli.

Treatment of leprosy:

Multidrug therapy regimens in treatment of leprosy (Modified WHO – recommended):

Leprosy type	Monthly supervised drug treatment	Daily self administered drug treatment	Duration of treatment
Paucibacillary – single lesion leprosy	Ofloxacin 400 mg Rifampicin 600 mg Minocycline 100 mg		Single dose
Pauci -bacillary (2-5 skin lesions) leprosy	Rifampicin – 600 mg	Dapsone – 100 mg	6 months
Multi -bacillary	Rifampicin – 600 mgClofazimine – 300 mg	Clofazimine – 50 mg Dapsone – 100 mg	12 months

Difference between Lepromatous Leprosy and Tuberculoid Leprosy:

Traits	Lepromatous leprosy	Tuberculoid leprosy
Number and distribution of skin and nerve lesions	Widely disseminated	One or few sites, asymmetsically distributed
Clarity of margin of skin lesionElevation of margin of skin lesionColour of lesion in dark skinColour of lesion in light skinSurface of skin lesion Central healing of the lesion Sweat and hair growth Loss of sensation	PoorNeverSlight hypopigmentationSlight erythema Smooth , shiny None Impaired late Late	GoodCommonMarked hypopigmentationCoppery or red Dry , scaly Common Impaired early Early and marked
Nerve enlargement and damage	Late	Early and marked
Bacilli	Many (5/6 or more)	Absent
Natural outcome	Progression	Healing

Complications of leprosy:

1. Anaesthesia of part or whole of the affected limb
2. Immunosuppression
3. Paralysis
4. Sepsis
5. Osteomyelitis
6. Amyloidosis
7. Nephritis
8. Exposure keratitis.

Lepra reaction:

Definition:

It is an acute exacerbation of clinical features that occurs due to an acute inflammation in pre-existing leprosy.

Types of Lepra reaction:

There are two types of Lepra reaction-

a) Type I
b) Type II

a) Type I:

Patients suffering from borderline tuberculoid leprosy develop this type of reaction where there are formation of new macules and rapid destruction of affected nerve(s).

Down grade reaction: When this reaction occurs before starting of the treatment.
Reversal reaction: When this reaction occurs after initiation of treatment.

Treatment of  type I lepra reaction:

• In mild cases- Tab. Aspirin is given at a dose of 600 mg -6 hourly
• In severe cases – Tab. Prednisolone is given at a dose of 40 – 60 mg – daily for at least 3 months and then tapering the dose for 3 – 9 months.

b) Type II (Erythema nodusum leprosa):

Patients suffering from borderline lepromatous and lepromatous leprosy develop this type of reaction where there are formation of macules and development of fever and lymphadenitis. Usually type II lepra reaction occurs after beginning of the treatment within two years of time.

Treatment of type II lepra reaction:

• In mild cases – Tab. Aspirin is given at a dose of 600 mg -6 hourly.
• In severe cases – Tab. Prednisolone is given at a dose of 20 – 40 mg – daily for at least 2 weeks and then tapering the dose.