159 - Leprosy Flashcards
Besides humans, M. leprae is also found as a zoonotic infection in _____ in the Southern United States, and recently in _____ in the British Isles
Armadillos
Red squirrels
More than 805 of all new cases are detected in only 3 countries
India
Brazil
Indonesia
Has the highest number of leprosy cases
India
Has the highest new case detection rate
Brazil
Special self-healing type of tuberculoid leprosy
Can be found as a single nodular lesion, but also as papules or plaques, usually on the face of the child
Infantile nodular leprosy
Special type of lepromatous leprosy
Has an ever higher bacillary load than the usual lepromatous leprosy, presenting as diffuse shiny nodules and papules
Histoid leprosy
Species in Lucio leprosy
Mycobacterium lepromatosis
Mycobacterium lepromatosis is found mainly in
Mexico
Caribbean
Triple Lewis response in normal skin
Erythema 5 to 10 seconds after intradermal injection of 1:1000 histamine
Secondary erythema two minutes after caused by capillary dilation
Wheal formation caused by exudation of liquid to the dermis
Response of lesional skin tointradermal injection of 1:1000 histamine
Incomplete Lewis response, with the absence of secondary erythema
Thinnest monofilament
Green
Thickest monofilament
Red
Loss of sensation using blue monofilament
Diminished light touch
Loss of sensation using purple monofilament
Diminished protective touch
Loss of sensation using red monofilament
Profound loss of protective sensation
Doubling time of M. leprae
13 days
Incubation time between infection and development of clinical disease
Usually between 3 and 7 years, although in some cases up to 20 years
Tuberculoid end of the spectrum having a strong Th_____ cell-mediated response whereas those at the lepromatous end have a skewed Th_____ response
1
2
TLR-1 and TLR-2 have a higher expression in
Tuberculoid leprosy
M. leprae can modulate NF-kappa beta activation in Schwann cells, a function that can be inhibited by
Thalidomide
ENL is an immunologic type _____ hypersensitivity response
III
Type 1 reaction or reversal reaction is a type _____ hypersensitivity immune response
IV
Characterized by sheets of predominantly spindle-shaped cells with nuclear pyknosis and foamy cytoplasm, vacuolated, and arranged in a storiform pattern
Resembles a fibrohistiocytic tumor
Histoid leprosy
The predominant lymphocyte present in ENL is the _____, whereas _____ predominate in the lepromatous leprosy
T-helper cell
T-suppressor cells
Lucio phenomenon is also knows as
Erythema necrotisans
One or a few hypochromic lesions
No autonomic alteration
No thickened nerves
Indeterminate leprosy
One or a few tuberculoid lesions
No more than one thickened nerve
Tuberculoid leprosy
One or a few infiltrated lesions
One or more thickened nerves
Borderline tuberculoid leprosy
One or many infiltrated lesions, that may be foveolar
Usually, more than one thickened nerve
Borderline leprosy
Many infiltrated lesions, associated or not to nodules
Many thickened nerves
Borderline lepromatous leprosy
Diffuse infiltration, nodules and autonomic dysfunctions
Many thickened nerves
Lepromatous leprosy
Y/N: Reactions never occur in indeterminate patients
Yes
Sudden worsening of skin lesions and nerve function impairment, with no apparent systemic involvement
Reversal reaction
Majority of the reactional episodes occur in
Borderline forms
Aggressive vasculitis with immune complex deposition affecting different organs
ENL
Predominant leprosy type in ENL
Lepromatous leprosy
Treatment for reversal reaction
Prednisone (1-2 mg/kg/d with slow taper ~3 mo)
Treatment for ENL
Thalidomide 100-400 mg/d AND Prednisone 1-2 mg/kg/d OR Pentoxifylline 400 mg thrice a day
The percentage of HIV and other viral infections in leprosy patients is high, indicating that all leprosy patients should be tested for
HIV
HBV
HCV
HTLV-1
Reactions vs relapses:
Respond well to treatment with antiinflammatory drugs
Reactions
Reactions vs relapses:
Slowly progressing, almost always with resurgence of primary lesions followed by the gradual appearance of new lesions
Relapses
3 groups of medications used for treating leprosy
Antibiotics
Antiinflammatory or immunosuppressants
Analgesic drugs
Clinically detected as a violet color on sclera, lips, and the extremities of fingers together with malaise, headache, and dyspnea
Methemoglobinemia
Main objection as far as patients are concerned is its affinity to fat tissue and macrophage deposits leading to skin hyperpigmentation
Clofazimine
Highly bactericidal
Adverse effects include face and neck redness, pruritus and cutaneous rash, loss of appetite, nausea, vomiting, and diarrhea, malaise, purpura, epistaxis
Rifampicin
Y/N: Pregnancy and breastfeeding contraindicate the use of multidrug therapy
No - do not contraindicate
