Leprosy Flashcards
Which organisms cause leprosy?
Mycobacterium leprae
Mycobacterium lepromatosis
What is worse? tuberculoid or lepromatous disease?
Lepromatous - more MB/higher AFB load
Describe the forms of disease moving from lowest AFB/highest CMI levels to highest?
TT -> BT -> BB -> BL -> LL
tuberculoid lepromatous
Symptoms of leprosy?
-Numbness in hands and feet
-Loss of function in hands and feet
-Deformities on hands and feet
-Painless ulcers or burns
-Nasal stuffiness
-Weakness in eyelids
-Reaction presentations
-Skin lesions (>95%)
Skin lesions of leprosy?
Indeterminate lesion - vague pale patch +/- anesthesia
Types of lesions –> macules, plaques, papules, nodules, infiltration
Tuberculoid leprosy lesion?
Well-defined
-Asymmetrical
-Definite anesthesia in lesion
Borderline tuberculoid lesion?
Ill-defined staellites
Definite anesthesia
Asymmetric
Borderline borderline lesion?
Circinate
Asymmetric
Definite anesthesia
Borderline lepromatous lesion?
Hypoesthetic patches
Variable lesion anesthesia
Symmetric
Lepromatous leprosy lesion?
Nodules and infiltration
Variable lesion anesthesia
Symmetric
What is the Ridley Jopling Classification
Tuberculoid
Borderling tuberculoid
Borderline borderline
Borderline lepromatous
Lepromatous leprosy
What are the nerve signs of leprosy?
- Enlarged nerves
- Dryness in hands and feet
- Loss of sensation in hands and feet
- Painless ulcers and wounds
- Weakness in motor function in hands and feet
- Deformities in hands and feet
Describe the nerve exam for leprosy?-
Nerves often enlarged: supraorbital, cervical, great auricular, median, ulnar, radial, radial cutaneous, common peroneal, posterior tibial
Assess:
-Sensation (monofilament test, ballpoint)
-Motor function (muscle strength scale 1-5)
-For nerve damage
Ocular symptoms of leprosy?
-Lagophthalmos
-Decreased corneal sensation
-Acute iritis
-Chronic iritis
-Cataract
-Blindness
What is the WHO disability grading for leprosy?
Eyes - 0 = normal, 2 = reduced vision, unable to count figers at 6m, lagophthalmos
Hands - 0 = normal, 1 = loss of feeling in the palm of the hand, 2 = visible damage to the hands such as wounds, claw hand or loss of tissue
Feet - 0 = normal, 1 = loss of feeling in the sole of the foot, 2 = visible damage to the foot such as wounds, loss of tissue or foot drop
Eyes, hands and feet are all graded separately by side (6 categories total)
Grade for the person as a whole is the highest score in any of the six places
What is the diagnosis methods for leprosy?
- Slit skin smears of suspected lesions and commonly affected sites (forehead, eyebrows, ear lobes) –> Z-N stain
- No serology
- No useful skin test
- Rarely nerve and skin biopsy for granulomas
What are the 3 cardinal signs of leprosy?
- Definite loss of sensation in a skin lesion consistent with leprosy (pale or reddish patch)
- Thickening of one or more peripheral nerves with loss of sensation and/or weakness of the muscles supplies by that nerve
- Skin smears/biopsy positive for acid fast bacilli in a slit-skin smear
Roughly 70% have one of these signs
6 Steps for diagnosis of leprosy?
- Hx
- Full exam of skin, nerves, deformities, ulcers, wounds
- Sensory testing
- Voluntary muscle testing
- Disability grading
- Slit skin smears BI/biopsy
WHO Paucibacillary classification of leprosy?
5 lesions or less
WHO Multibacillary classification of leprosy?
6 lesions or more
*If skin smear positive, patient classified as MB whatever the number of patches
What is the treatment of PB leprosy?
-6 mo of treatment
3 drug MDT:
-Rifampicin once a month
-Dapsone daily
-Clofazimine daily
What is the treatment of MB leprosy?
-12 mo of treatment
3 drug MDT:
-Rifampicin once a month
-Dapsone daily
-Clofazimine daily
Adverse effects of dapsone?
Anemia
Hypersensitivity rxn
Adverse effects of clofazimine?
Hyperpigmentation
Ichtyosis
Adverse effects of rifampicin?
Orange urine/tears x1-2d
DDx for leprosy lesions?
Pityriasis versicolor
Fungal infection
Eczema
Psoriasis
Vasculitis
Sarcoid
SLE
Erysipelas
Vitiligo
Polyneuropathy
Granulomatosis with polyangitis
Amyloid
Cutaneois lymphoma
Syphilis
Cutaneous leish
Post-kala-azar dermal leishmaniasis
Cutaneous TB
What are the types of borderline leprosy and their bacteriological index?
Borderline tuberculoid - 0-1+
Borderline borderline - 1-3+
Borderline lepromatous - 3-5+
What is the type of polar tuberculoid leprosy?
Tuberculous tuberculoid - 0
What is the polar lepromatous type of leprosy?
Polar lepromatous 5-6+
What are the MB types of leprosy?
BT
BB
BL
LL
What are the paucibacillary leprosy types?
TT
BT
What are the 4 leprosy reactions?
Type 1 rxns (most common)
Type 2 rxns (erythema nodosum leprosum - ENL)
Silent neuropathy
Lucio’s phenomenon
Describe a type 1 rxn?
Borderline forms of leprosy
Skin and nerve inflammation
Nerve function impairment
-Can occur prior to, during or after MDT
-Acute inflammation in skin, nerves or both
-Typically affects pre-existing skin lesions
-Can have facial and peripheral edema with it
-May lead to permanent loss of nerve function
Pathophys of type 1 rxns?
-M leprae antigens in skin and nerves
-TNF stimulated
-TLR-2 expressed in Schwann cells
What is the treatment of type 1 rxns?
Prednisolone 30-60 mg daily reducing over 20 weeks to zero
Corticosteroid-sparing agents - azathioprine, ciclosporin, methotrexate
Describe ENL reaction?
Lepromatous leprosy
Nerve function impairment
Can occur before, during or after MDT
Often recurrent or chronic
Multisystem disorder - fever, malaise, painful erythematous cutaneous nodules, edema, arthritis, iridocyclitis, neuritis, nephritis, orchitis
Treatment for ENL rxns?
Thalidomide 300-400 mg PO per day
Prednisolone
Adverse effects of thalidomide?
-Teratogenic if taken dyas 20-34 of gestation
Chronic complications of leprosy?
Neuropathic pain (20-30%)
Tx:
-Paracetamol/NSAID
-Amitriptyline
-Gabapentin
-Carbamazepine
