Leprosy Flashcards
Leprosy - organisms
Mycobacteria leprae + lepromatosis
Intracellular orgnism
Not possible to culture
Long IP - 3-5 years [range 6 months to 20 years]
Leprosy - epidemiology
Burden 174,000 new cases 2022
Leprosy - transmission
Person to person [bacilli in nasal droplets]
Animal reservoirs [armadillo, squirrels]
Hypothetical transmission - environmental reservoirs, tickers and free living amoeba
Leprosy - number of infected people who develop disease
<5% progress to disease
Tuberculoid - stronger cell mediated immunity
Lepromatous - lower immunity - higher bacilli burden in tissues
Leprosy - presentation
Hands and feet = numbness, loss of function deformities
Painless ulcers/burns
Nasal stuffiness
Eyelid weakness
Skin lesions - >95% have skin lesions
-Types of lesions - macules, plaques, papules, nodules, infiltration
Reaction presentation = fever, joint pain, inflamed skin
Leprosy - clinical spectrum [Ridley Jopling classification]
Tuberculous tuberculoid [TT]:
Well-defined lesions with clear area of anaesthesia
hypopigmented plaque
Common sites - buttocks, face, extensor surfaces of limbs
Boderline tuberculoid [BT]:
Ill-defined satellite lesions with anaesthesia
Borderline leprosy [BB]:
Circinate poorly defined raised lesion
Borderline lepromatous [BL]:
Multiple irregular hypoesthetic patches
Lepromatous leprosy [LL]:
Symmetrical, multiple lesions
Nasal stuffiness, discharge
Oral lesions, hoarseness
Nasal bridge collapse
Leonine face
Leprosy - nerve signs
Palpable enlarged nerves:
-Supraorbital
-Great auricular
-ulnar
-Median
-Radial cutaneous
-Common peroneal
Leprosy - WHO disability grading
Eyes, hands, feet
0 - 2
Leprosy - lab diagnosis
No useful serological test
Skin and nerve biopsy - granulomas
Slit skin smears - commonly affected sites sampled - forehead, eyeborws, ear lobes
-Bacteriological index: ZN staining, logarithmic scale [0 - 6+]
Leprosy - cardinal signs
Definite loss of sensation in skin lesion
Thickening of one or more peripheral nerves
Skin smear/biopsy positive for acid fast
Leprosy - WHO classification
Paucibacillary [PB]
-5 lesions or less
-Tuberculoid
Multibacillary [MB]
-6 or more lesions
-Skin smear positive = multibacillary
-Lepromatous
Leprosy - treatment
Paucibacillary:
-6 months
-2 drugs: rifampicin [monthly] and dapsone [daily]
Multibacillary:
-12 months
-3 drugs: rifampicin [monthly], dapsone [daily] and clofazimine [daily]
2nd line = minocycline, ofloxacin, perfloxacin, clarithromycin
Monthly alternative = rifampicin, ofloxacin, minocycline
Leprosy - Dapsone side effects
Anaemia
HS reaction - particularly G6PD def
Leprosy - Clofazimine side effects
Hyperpigmentation
Ichytosis - scaling skin - particularly shins
Leprosy - Rifampicin
Orange urine/tears, hepatotoxicity
