Leprosy Flashcards
(26 cards)
What are the causes of leprosy?
Mycobacterium leprae
Mycobacterium Lepromatosis
What re the routes of transmission of Leprosy?
- From nasal secretions and skin lesions of an infected person via close contact.
- Contact with Armadillos of the species Dasypus novemcinctus
What are the risk factors of developing Leprosy?
1.Close contact
2.Age : between the ages of 5-15 and older than 30yrs
3.Genetics: NOD2 variant
4.Immunosupression : e.g. HIV , Chemotherapy
Describe the pathogenesis of Leprosy?
It invades through the epithelium and into peripheral nerves.
It is an obligate parasite that lives within macrophages
It grows more efficient and fastest at temperatures of 27-33 degrees so affects the coolest part of the body- Skin, eyes, nose and mucous membranes of the respiratory tract)
What are the cardinal features of leprosy?
- Skin patch with loss of sensation (could be hypopigmented or erythematous)
- enlarged peripheral nerve with loss of sensation
- positive slit-skin smear
How would you test for sensation on the skin lesions?
By assess for :
Light touch
Pin Prick
Temperature discrimination
Vibration
Perception
Which peripheral nerves would you palpate to assess for enlargement?
Great auricular n.
Ulnar n.
Radial cutaneous n.
Median n.
Lateral popliteal n.
Posterior tibial n.
What are the consequences of paralysis of the intrinsic foot muscles?
Unstable gait
Flattening of the arches
Arthrotic changes
Arthritis
Ulceration deformity
How is a slit skin test done?
Pinch the site tight
Incise
Scrape and collect material
Smear on the slide
Air dry and fix
Stain (Ziehl -Neelsen)
From which body parts is a slit skin smear test done?
Earlobe
Chin
Extensor forearm
Dorsal fingers
Buttocks
Knees
What is an indeterminate lesion? And where does it normally occur?
Indeterminate leprosy is an early, non-specific stage of leprosy caused by Mycobacterium leprae. It is characterized by a few mild skin lesions, which may be flat or slightly raised, and there is often no significant loss of sensation at this stage.
In endemic areas and in children with contact with active leprosy.
Describe the leprosy spectrum and how it differs in terms of antibodies, cell mediated immunity and bacterial load.
Tuberculoid (TT),
borderline tuberculoid (BT),
mid borderline (BB),
borderline lepromatous (BL),
lepromatous leprosy (LL)
Describe the difference between Tuberculoid leprosy and Lepromatous leprosy?
The number of bacteria
Degree of infectiousness
Strength of immunity
Clinical features (skin lesions etc)
Granuloma formation and activation of macrophages
Peripheral nerve damage
sensory loss
Visible nerve enlargement
Predominating cells
Rection to the slit skin test
Presence of erythema nodosum
How to diagnose
Treatment
What facial feature of leprosy is seen in Lepromatous leprosy but not tuberculoid? Describe it?
Facies Leonina
1.Thick and lumpy earlobe/Pinna
2.Loss of eyebrows (Madarosis)
3.Deformed nostril
What is the treatment for Leprosy? And how does it differ between MB and PB?
1.Rifampicin: 600 mg once a month
2.Clofazimine: 300 mg once a month, and 50 mg daily
3. Dapsone: 100 mg daily
PB : 6 months
MB: 12months
Dosages differs between adults, children (10-14 years) and Children below 10 years or less than 40kg
How do you treat rifampicin resistant leprosy?
For first 6months daily
Ofloxacin
Minocycline/ clarithromycin
Clofazimine
For the next 18 months daily
Ofloxacin, minocycline and clofazimine
or Ofloxacin clofazimine
What are the treatment options for rifampicin and ofloxacin resistance?
Clarithromycin + minocycline and clofazimine for first 6 months daily
THEN
Clarithromycin or minocycline + clofazimine for 18 months
How do you prevent Leprosy?
For adults and children (aged above 2 years)
who are in regular contact with leprosy
patients, the guidelines recommend the use
of single-dose rifampicin
What is a lepra reaction?
Lepra reactions are inflammatory
reactions occurring in leprosy, due to circulating immune complexes, vasculitis
, or T-cell reaction which may be induced by treatmen
What are the 2 types of leprosy reactions?
Type I= reversal reaction (RR)
– Type IV Coombs & Gell
– Delayed type hypersensitivity
– Chronic course
Type II = Erythema
nodosum leprosum (ENL)
– Type III Coombs & Gell
– Immune complexes
with cutaneous and systemic
vasculitis
– Intermittent of continuous
What are the characteristic features of type 1 reaction? In which type of leprosy does it occur.
Increased inflammation in established skin lesions
Acute nerve pain or tenderness and loss of function
Recent(< 6months ) or progressive nerve function impairment in the absence of painful nerves
Emergence of new lesion
Bordeline Leprosy (BB , BT,BL)
What are the characteristic findings of type 2 reaction and in which type of leprosy does it occur?
Fever, myalgia, malaise
* Arthralgia
* Iridocyclitis
* Hepato-splenomegaly
* Orchitis
* Lymphadenitis
* Glomerulonephritis
* Skin nodules
Secondary amyloIdosis (Amyloid A protein)
BL and LL
When do leprosy reactions occur?
Before, during or after treatment.
What is the treatment(1st and 2nd line) for Leprosy reactions?
1st : Prednisolone
2nd: Ciclosporin
