LEPROSY 2 Flashcards
1
Q
- Delayed hypersensitivity reaction associated with sudden alteration of CMI status
- Marked by infiltration of lesion by activated CD4+ T lymphocytes (T helper cells)
- “Reversal reaction” - upgrading of CMI status
- Usually observed in the borderline portion
- Skin lesions: acute swelling and redness
- Nerves: painful and tender of neuritis, consequent nerve damage and disfigurement; severe - nerve abscesses
- “Silent neuritis” - may lead to sensory and motor impairment in the hands, feet and face
- Arthralgia or arthritis sometimes occur, fever and malaise, tenosynovitis, edema of the feet and hands
A
Type 1 Leprosy Reaction (T1R)
2
Q
- An immune complex-mediated syndrome, that causes inflammation of the skin, nerves and other organs, as well as general malaise
- Occurs mostly during multidrug therapy, can also develop in untreated patients
- Evanescent, pink-to-red maculopapular, papular, nodular, or plaque lesions accompanied by malaise and fever, with or without painful swelling of the joints
= Present on the outer aspects of the thighs, legs & face
= Painful or tender and warm, blanch with light finger pressure, last for a few days - Erythema nodosum necroticans: vesicular, pustular, bullous, and necrotic and break down to produce ulceration
- Severe: swollen, painful, and tender nerve trunks with sensory and motor deficits
A
Type 2 Leprosy Reaction (T2R) - ENL (Erythema Nodosum Leprosum)
3
Q
Example of Type III hypersensitivity reaction or Arthus phenomenon
A
Type 2 Leprosy Reaction (T2R) - ENL (Erythema Nodosum Leprosum)
4
Q
- May be a variant of erythema nodosum necroticans
- Marked vasculitis and thrombosis of the superficial and deep vessels - hemorrhage and infarction of the skin
- Begins as slightly indurated, bluish-red, ill-defined, painful, and rarely palpable plaques with an erythematous halo
- After a few days, they become purplish at the center; a central hemorrhagic infarct may develop, and a necrotic eschar that detaches easily and leaves an ulcer of irregular shape
- Remains afebrile throughout
A
Lucio’s Phenomenon
5
Q
- Used for the sensory, motor, and/or autonomic nerve deficits that occurs because of the pathologic processes
- Neuritis (nerve inflammation) - subacute, demyelinating and unremitting event involving cutaneous nerves and larger peripheral nerves
- Can occur at any time during leprosy, but more common and severe during leprosy reactions (mainly T1R)
- Can lead to secondary impairments - muscle atrophy, mobile- and fixed-joint contractures, bone absorption of digits, and cracks and wounds
A
Leprosy Reactions:
Nerve Function Impairment, Neuritis, and Disfigurement
6
Q
progressive sensory or motor impairment in the
absence of symptoms in Leprosy Reaction
A
“Silent neuritis” or “Quiet nerve paralysis”
7
Q
Diagnosed when 2 or these 3 signs are present of leprosy
A
- Hypopigmented or erythematous skin lesions with definite loss or impairment of sensation
- Involvement of peripheral nerves, as demonstrated by definite thickening with sensory impairment
- A positive result for AFB in slit-skin smears, presence of AFB in a skin smear or biopsy sample, or a positive result in a biopsy PCR
8
Q
Testing of Skin Sensation
A
- Light touch sensation
- Pain
- Thermal sensation
9
Q
Slit-Skin Smear
A
- Taken from four sites: right earlobe, the forehead above the eyebrows, the chin, and the left buttock in men or left upper thigh in women
- Stained using Ziehl-Neelsen reagent and examined with a light microscope
10
Q
Skin biopsy
A
- Done to confirm the diagnosis of leprosy, to classify the disease, to support the diagnosis of reactions, and to determine cure after the completion of multidrug therapy
- Macular lesions: taken from the middle of a lesion
- Plaques: active indurated edge
- Numerous with different morphologies: more than one biopsy
11
Q
- is a specific lipid on the M. Leprae cell wall
- used for serologic diagnosis of leprosy
=Multibacillary (90-95%), Paucibacillary (25-60%) - ML flow test: developed for detection of antibody to PGL-1
= Multibacillary (92-97%%), paucibacillary (32-40%)
A
PGL-1 Antibody Test
12
Q
- Measures cellular immunity against lepromin
-mThe reaction is measured as induration in millimeters
3-4 weeks after intradermal inoculation. - Negative lepromin test: LL or BL leprosy (indicating the
lack of a protective cellular response
A
Lepromin Test (Mitsuda Skin Test)
13
Q
Significantly enhances the detection of M. Leprae, especially in bacteriologic indexnegative leprosy and cases that do not fulfill the criteria for cardinal signs of leprosy
- Sensitive to as few as 1-10 bacilli and yield positive results in 60-7% of smear negative cases
A
Gene Amplification (PCR) Technique
14
Q
- Ulnar and median nerves, posterior tibial nerve - usually tested for touch sensation
- Semmes-Weinstein monofilament (SWM) test - most reliable test
- Impairment is <6 months, and/or new nerve function impairment is diagnosed: glucocorticoid should be given
- WHO recommends ballpoint pen be used, if filaments not available
A
Touch Sensation Testing
15
Q
Voluntary Muscle Testing
- Facial nerve -
- Ulnar nerve -
- Median nerve -
- Radial nerve -
- Common peroneal nerve -
A
- Facial nerve - eye closure
- Ulnar nerve - finger abduction;
- Median nerve - thumb opposition;
- Radial nerve - wrist extension;
- Common peroneal nerve - ankle extension
