22.02.2016 dvl
TRANSCRIPT
HistoryDefinition: Leprosy is a chronic systemic disease
caused by Mycobacterium leprae manifesting as development of specific granulomatous or neurotrophic lesions in the skin, mucous membrane, eyes nerves, bones and viscera.
Oldest infection known to mankind
Synonyms: Hansen’s disease, ‘Kushtha roga’
Transmission of LeprosyRespiratory route: inhalation of bacilli-laden
droplets
Cutaneous: skin to skin contact
GIT : ingestion of food
Intradermal : inoculation by tattoos } Not Yet Proven
Epidemiological factorsOccurs at all age groupsPeak age of onset : Between 10 – 20 yearsMales > FemalesChildren most susceptibleImmune status ( host resistance)OvercrowdingLow socioeconomic status
Immunity and Leprosy
Host resistance ExcellentGood
Fair
Poor Very poor
Clinical manifestationNo infectionSubclinical infection with spontaneous regression Indeterminate, pure neuritic,tuberculoidMid-borderline,borderline-lepromatous
Lepromatous
Mycobacterium LepraeObligate, intracellular, acid-fast bacillus Affinity for skin, nerves and muscle tissue Found in macrophages, histiocytes and Schwann
cells. Non cultivable Grown in animal modelsClosely resembles M.tuberculosis, but less acid-
fast. Multiplies in 11-13 days.
Classification
The Ridley Jopling classificationIndeterminateTuberculoidBorderline: borderline-tuberculoid,
mid-borderline, borderline-lepromatous
LepromatousPure neural, Maculoanaesthetic - Indian classification
ClassificationPaucibacillary Leprosy(PB): Indeterminate leprosy (I) Tuberculoid leprosy (TT) Borderline tuberculoid (BT) Pure neuritic (PN)* Multibacillary Leprosy(MB): Midborderline leprosy (BB) Borderline lepromatous (BL) Lepromatous leprosy (LL) * Asymmetric nerve involvement with no skin lesion
and usually of tuberculoid origin.
Tuberculoid (TT) Single or few, asymmetrical, well-defined,
erythematous or copper-coloured patches Sensations - Absent Nerves - thickened, presence of feeding nerves,
abscesses Skin smears - Negative Lepromin test - Strongly positive Course - Relative benign and stable, with good
prognosis.
Borderline leprosy
Common type of leprosy Subdivided into BT, BB & BL. Course - Unstable with variable prognosis , may
progress to sub-polar LL leprosy. Most prone to reactions. Lepromin test -Negative ,weakly positive in BT.
Borderline Tuberculoid (BT) Few asymmetric, hypopigmented or skin coloured
macules, plaques with ill defined marginsPresence of satellite lesion near the advancing
margin of patchSensory impairment - MarkedNerve involvement - Marked and asymmetrical
Midborderline leprosy (BB)Unstable form, reactions frequent Annular lesions with characteristic punched out
appearance (inverted saucer shaped) Sensory impairment - Moderate. Nerve involvement - Marked and asymmetrical.
Borderline lepromatous leprosy (BL)Multiple shiny macules, papules, nodules and
plaques with sloping edges Sensory impairment - SlightNerve involvement - Widespread and less
asymmetrical. Glove & stocking hypoaesthesia
Lepromatous leprosyHypopigmented, erythematous or coppery, shiny
macules, papules, nodules Lesions symmetrically distributed, small, multiple,
shiny with normal or mild sensory loss Leonine facies: Infiltration of skin with nodules, loss
of eyebrows and eyelashes Nerve involvement symmetrical; glove & stocking
anaesthesia Lepromin test - Negative
Indeterminate leprosyAsymmetrical, single /multiple hypopigmented, or
faintly erythematous and ill-defined macules.Sensation - Normal or slightly impairedPeripheral nerves - NormalSkin smears - NegativeLepromin test - Unpredictable and variableCourse - Usually self limiting ,may progress to
other forms of leprosy.
Pure Neuritic leprosyNeuritic manifestations -Tingling, heaviness and
numbness, paresis, hypotonia, atrophy, claw hand and toes, wrist-drop, foot-drop.
No skin lesion.Other changes-Anhidrotic, dry glossy skin, blisters,
neuropathic ulcers, decalcification, bone resorption.
Pure Neuritic leprosyLepromin test -Slightly positive.Course-Spontaneous regression or progression to
TT leprosy.Silent neuritis (silent neuropathy) Sensory or motor impairment without skin signs of
reversal reaction or ENL ,tenderness, paraesthesiae or numbness.
Special forms of LeprosyLucio Leprosy: Rare form of lepromatous leprosy, described in Mexico. Diffuse widespread infiltration of skin, loss of body hair, loss of eyebrows & eyelashes, and widespread sensory loss.‘Lepra Bonita’ (Pretty leprosy)Elderly persons with diffuse infiltration of face smoothes out wrinkles, giving youthful appearance. Histoid leprosy:BL patients with irregular or poor treatment complianceDrug resistant cases
Eye Involvement in LeprosyLagophthalmos (partial/complete,
unilateral/bilateral) Conjunctivitis Exposure keratitis and corneal ulcersMadarosis, trichiasis leading to corneal vascularity
and opacity Dacryocystitis (acute,subacute or chronic) Nodules on sclera, episcleritis, scleritis Corneal nodules and lepromatous pearls Microlepromata, nodules on iris and ciliary body
Nerve Involvement in LeprosySensory involvement - Anaesthesia in hands & feet,
glove and stocking anaesthesia, repeated traumaMotor involvement- Wasting and paralysis of
musclesAutonomic involvement -Icthyosis, loss of hair and
sweating.
Other featuresNasal stuffiness / crustingEpistaxisHoarseness of voiceGynaecomastiaSaddle noseBone resorptionLymphadenopathy
Differential diagnosis of leprosy
Macular lesionsVitiligo Occupational leucoderma Tinea versicolor Pityriasis alba Post kala azar dermal leishmaniasis Naevus depigmentosus Scars
Differential diagnosis of leprosy
Infiltrated lesionsLupus vulgarisLupus erythematosusGranuloma annulareAnnular syphilidesPost kala azar dermal leismaniasis (infiltrated
lesions)SarcoidosisPsoriasis
Differential diagnosis of leprosy
Nodular lesionsPost kala azar dermal leismaniasis Cutaneous leismaniasisSyphilisOnchocerciasisSarcoidosisLeukaemia cutisMycosis FungoidesNodules of neruofibromatosis
Differential diagnosis of neurological conditionsSensory impairment with or without muscle wastingPeripheral neuropathy Diabetic neuropathyPrimary amyloidosis of peripheral nerves Congential sensory neuropathy Syringomyelia Tabes dorsalis Thoracic outlet syndromeAlcoholic neuropathy
Diagnosis
Cardinal signs of leprosySensory impairment in affected areasEnlargement of peripheral nerves associated with
signs of peripheral nerve damageFinding acid-fast bacilli in the lesions
Clinical examinationType and number of skin lesionsSensory impairment Motor examinationNerve examination SweatingLoss of hair
Clinical examination: SensoryTouch Tested with wisp of cotton,nylon thread or feather.
Temperature Tested with two test tubes – one containing hot water and other cold
Pain Tested by pin prick
Clinical examination : Motor Testing of motor power- Done clinically
Electro-diagnosis - Employed in very early cases. Electrical stimulator using faradic and galvanic current used to test muscle power.