Classification & Clinical Features of Leprosy

04/17/2023 HANSEN's DISEASE 1

CLASSIFICATION & CLINICAL FEATURES OF LEPROSY

ByDR UMAR,F.A.

RHEUMATOLOGY UNITDEPT OF MEDICINE.

ABUTH-ZARIA.


FORMAT

• INTRODUCTION/DEFINITION• BASIS FOR CLASSIFICATION OF HANSEN’S

DISEASE• CLASSIFICATION OF HANSEN’S DISEASE• PECULIARITIES OF EACH SUBCLASSIFICATION• CLINICAL FEATURES OF HANSENS DISEASE• COMPLICATIONS• DIAGNOSIS OF LEPROSY


HANSEN’s disease

• Leprosy is a chronic infectious systemic disease that primarily affects the peripheral nerves & skin.other organs that can be affected in long term include nasal mucosa,larynx,eyes,testis,liver,kidney etc.

• The disease is caused by a rod shaped bacillus called mycobacterium laprae & mycobacterium lepromatosus

• M laprae was discovered by G.A Hansen in Norway in 1873.It’s a slowly growing obligate intracellular pathogen incapable of independent existance outside its host.


contd• The organism cant be grown in the laboratory• Can only be grown in armadillos & immuno-

compromised mice• Mycobacterium leprae has an average doubling time

of 12-14 days• Human, Armadillos,& 3 species of monkeys-

(chimpanzee, Sooty mangabey & Cynomolgus macaques) are the only known sufferers from Hansen’s disease.

• Disease can take up to 20-40 years before manifesting.• Above constitutes many impediments to the study,

prevention & control of this ancient disease.


World distribution of leprosy

http://en.wikipedia.org/wiki/File:Lepra_2003.png


Magnitude of the problem• The incidence of leprosy in low endemic area like USA= 100

case/year• New case may reach 5000-10,000/year in high endemic

areas(Angola, Brazil, Central Africa Republic, DR Congo, India, Madagascar, Mozambique, Nepal & Tanzania)

• Global prevalence of leprosy according WHO 2008 report is still > 1case/10,000 population.

• 2008 global registered prevalence from 118 countries =212,802.

• N@ of new cases in 2007 is a staggering 254,525. representing 4% drop compared to 2006.

• Over 50 million have been treated & cured of the disease.• Over 3 million have been permanently deformed by the

disease, resulting in loss of job, societal stigmatization & isolation.

http://en.wikipedia.org/wiki/File:Lepra_2003.png


Lepers’ colony

http://en.wikipedia.org/wiki/File:Bundesarchiv_Bild_105-DOA0199,_Deutsch-Ostafrika,_Leprakranke.jpg


The disease

• Mode of transmission of disease is via respiratory system, through nasal droplets.

• Transmission via broken skin is a possibility.• The primary sites that are affected by leprosy

are superficial site of the skin & peripheral nerves as the bacteria have predilection for low temperature sites as it enhances its survival



Classification schemes for HDWHO RIDLEY-JOPLING MeSH LEPROMIN TEST

PAUCIBACILLARY INDETERMINATE(I)TUBERCULOID LEPROSY(TT)BORDERLINE TUBERCULOID(BT)

TUBERCULOID POSITIVE

MULTIBACILLARY MID BORDERLINE OR BORDERLINE BORDERLINE(BB)

BORDERLINE

MULTIBACILLARY LEPROMATOUS LEPROSY(LL)BORDERLINE LEPROMATOUS(BL)

LEPROMATOUS NEGATIVE


Value of classification• An understanding of the spectral concept help in the understanding of the

multiplicity of the clinical manifestation of this disease• Tuberculoid leprosy is associated with severe nerve damage, lepromatous

leprosy with chronicity & long term complications• Spontaneous healing can occur near the tuberculoid pole but almost

never in the lepromatous pole• Polar disease are immunologically stable & are unlikely to change their

position on the spectrum,meaning that ,type 1 reactional states are not often encountered.

• Borderline disease are unstable & may move either way along the spectrum.Such a shift in cellular immunity is often associated with an acute reaction(type 1),which may occur spontaneously or with treatment causing severe multiple nerve damage.

• Lepromatous leprosy are likely to suffer reactions mediated by antigen antibody complex(type 2 reaction)

• Classification of leprosy provides a basis for matching of research patients• Classification of patients seen during a survey may help in the planning of

control measures



Classification of leprosy

• Leprosy usually affects the skin,nerve & nasal mucosa but presents with varying degree of clinical presentation.

• Leprosy is a spectrum disease.the point any patient occupy on the spectrum is reflective of the balance btwn cellular immunity(Th1) & bacilli multiplication & consequent tissue invasion.



Classification of leprosy

• Pts with good celluler immunity develop tuberculoid leprosy(TT) limited to the skin & nerve.

• Those with poor immunity develop lepromatous leprosy(LL) xterised by symmetric skin lesions,nodules,plaques & thickened dermis and also have widespread systemic affectation.

• In btwn these two extremes are the borderline disease-borderline tuberculoid(BT),mid borderline or borderline borderline(BB) & border line lepromatous.



Classification continued• Indeterminate leprosy=earliest form of lesion,presents as

1 or 2 hypopigmented anaesthetic patch which can heal spontaneously or progress and enter the spectrum.

• Tuberculoid leprosy(TT)• Borderline tuberculoid(BT)• Midborderline/Borderline borderline(BB)• Borderline lepromatous(BL)• Lepromatous leprosy(LL)• TT-------------BT---------------BB--------------BL------------------LLpolar dx ----------borderline disease---------- polar dx

• Moving from left to right,the following occurs• Decrease in cellular immunity & failure of disease containment• Increase in bacillary multiplication & tissue invasion.• Increase in number of skin lesion but decreased definition of lesion• Positive to negative lepromin test• Increase in bacillary index & morphogenic index



Clinical features of tuberculoid leprosy-TT

• Can be either one large red patch with well-defined raised borders or a large hypopigmented asymmetrical spot

• Lesions become dry and hairless • Loss of sensation may occur at site of some lesions

bcs of damaged peripheral nerves• Tender, thickened nerves with subsequent loss of

function are common • Spontaneous resolution may occur in a few years

or it may progress to borderline or rarely lepromatous types



BORDERLINE TUBERCULOID LEPROSY

• Similar to tuberculoid type except that lesions are smaller and more numerous

• Disease may stay in this stage or convert back to tuberculoid form, or progress



BORDERLINE BORDERLINE

• Disease is of intermediate severity,most common form of leprosy.

• Skin lesions resembles tuberculoid leprosy but are more numerous & irregularly shaped.

• Large patch may affect a whole limb• Peripheral nerve involvement with weakness & loss of sensation

is common. • Sensory loss is moderate • Midborderline disease is characterised by instability,disease

may advanced towards the lepromatous pole(downgrading) or undergo a reversal reaction becoming more like a tuberculoid leprosy(upgrading)



Borderline lepromatous

• Numerous lesions of all kinds, plaques, macules, papules and nodules. Lesions looking like inverted saucers are common

• Hair growth and sensation are usually not impaired over the lesions



Lepromatous leprosy• Characterised by presence of symmetric skin lesions of various types • Lesions like plaques, macules, papules and nodules are seen• Early symptoms include nasal stuffiness, discharge and bleeding, and

swelling of the legs and ankles • Left untreated, the following problems may occur:

– Skin thickens over forehead (leonine facies), eyebrows and eyelashes are lost(madarosis), nose becomes misshapen or collapses, ear lobes thicken, upper incisor teeth fall out

– Eye involvement causing photophobia (light sensitivity), glaucoma and blindness

– Skin on legs thickens and forms ulcers when nodules break down – Testicles shrivel causing sterility and enlarged breasts (males) – Internal organ infection causing enlarged liver and lymph nodes – Voice becomes hoarse due to involvement of the larynx

• Slow scarring of peripheral nerves resulting in nerve thickening and sensory loss. Fingers and toes become deformed due to painless repeated trauma.


http://dermnetnz.org/common/image.php?path=/bacterial/img/leprosy3.jpg



Summary of characteristics of leprosy at the polesmanifestations Lepromatous leprosy Tuberculoid leprosy

Number & distribution of skin nerve lesions

Widely disseminated & symmetrical

One or few sites assymetrical

Definition of skin lesions

Clarity of margin poor good

Elevation of margin never common

Colour of lesion in dark skin Slight hypopigmentation Marked hypopigmentation

Surface character Smooth,shiny Dry,scaly

Central healing None Common

Sweating & hair growth Impaired late Impaired early

Loss of sensation late Early & marked

Nerve enlargement & damage

late Early & marked

Bacillary index Many (5 or 6+) absent

Lepromin test negative positive

Natural outcome progression Healing


Summary of systemic manifestation of HDSystem Manifestation

MusculoskeletalMechanism-sensory neuropathy -immobility -chronic ulceration

Indolent ulcers,marjolin’s ulcer,osteomyelitis,septic arthritis,acro-osteolysis,osteoporosis,pathological fractures,charcot arthropathy,myopathy.

Eyes Mechanism-1.Anaesthesia & exposure 2.Bacillary invasion ,infection 3.Hypersensitivity

Conjuctivitis,keratitis,uveitis,triachiasis,ectropion,entropion,lagophtalmos,glaucoma,cataract,anterior/posterior synaechea,sicca symptoms,optic atrophy.

Neurologic Mechanism-reactional states/bacillary inv

Sensory, Autonomic & Motor dysfunction

Endocrine Testiculer damage/atrophy,secondary gynaecomastia.Azoospermia,sterility

ENT Sinusitis,septal/palate perforation & obstructn.

Larynx Hoarseness of the voice,stridor.

Kidneys Immune complex nephritis,interstitial nephritis,Amyloid kidney

Generalised lymphadenopathy 90% lepromatous pts,70% tuberculoid pts


Sites of predilection of nerves swelling/injuryNerve Site of predilection to injury

Ulnar nerve Above the olecranon groove

Posterior tibial nerve Behind the medial maleoli

Common peroneal(lateral popliteal ) Lateral popliteal fossa

Facial nerve

Great auricular nerve Upper sternomastoid

Median nerve Proximal to the flexor retinaculum

Radial nerve Upper humerus below deltoid insertion

Anterior tibial Lateral to Halucis longus tendon

Supra-orbital Above the supra-orbital margin


Diagnosis of HD

• Anaesthesia-of individual patch or in the distribution of the large peripheral nerve.

• Charcateristic skin lesion-hypopigmented macules,patches etc

• Thickened nerves at the site of predilection• Acid fast bacilli in skin smear in lepromatous &

borderline leprosy• Nb-at least 2 of the 1st 3 cardinal signs or the 4th

should be present for the diagnosis of leprosy to be made.



AFB detection

• Mycobacterium laprae on ZN stain


http://en.wikipedia.org/wiki/File:M_leprae_ziehl_nielsen2.jpg


Assesment of bacillary & morphogenic indices

Bacillary index -is a measure of the density of afb on ZN staining• 6+= >1000 bacilli in an average field• 5+= 100-1000 bacilli in an average field• 4+= 10-100 bacillin in an average field• 3+= 1-10 bacilli in an average field• 2+= 1-10 bacilli in 10 fields• 1+= 1-10 bacilli in 100 fields Morphological index• Defined as the % of solid(morphologically normal)staining

bacilli.• MI is a useful index of progress under treatment & changes

more rapidly than the bacillary index



Lepromin test• Lepromin test is a crude semi standardised preparation of bacilli from

a lepromatous nodule or an armadillo liver.• It is a delayed hypersensitivity reaction to the bacilli• 0.1ml is injected intradermally & the site is inspected after

72hrs(Fernandez reaction) & 3 or 4 wks(Mitsuda reaction) for a palpable nodule whose diameter is measured & graded thus

• No nodule negative• 1-2mm doubtful• 3-5mm +• Over 5mm ++ • Ulceration +++• The test is not specific to leprosy & hence cant be relied solely on for

diagnosis.• It’s positive in borderline & tuberculoid leprosy & negative in

lepromatous/borderline lepromatous.Hence can be used to distinguish btwn the 2.



Hansen’s disease


Differential diagnosis

• As leprosy is a disease with wide spread manifestation,it’s differential diagnosis is myriad and needs careful consideration given the stigma attached to leprosy(leprophobia!)

• Good history,physicals including test for sensation is key to distinghising these conditions from hansen’s disease.


Differential diagnosis of leprosy Macular lesions• Birth marks -usually present from birth,usually dont alter their

appearance over the course of time.They have irreguler bizarre edge,there is varying degree of hypopigmentation even within the same lesion.The texture & character of the skin is normal,no aneasthesia.

• Vitiligo-complete depigmentation of any size & shape,no anaesthesia.

• Post-inflammatory hypopigmentation from previous skin disease eg endemic syphilis,yaws,onchocerciasis,contact dermatitis,burns.

• Tinea vesicolor - can be hypopigmented,hyperpigmentred or erythematous & covered with white floury scales.Individual lesions are discrete with clear edge.They often fuse to cover large areas.lesions are usually confined to an area of the skin,usually the trunk.Lesion are not anaesthetic,no AFB seen.


Differential diagnosis contd• Papules /Plaques /annular lesion • Ring worm-have preference for warm moist area(cf with Mb

laprae prefence for cold part areas of the body) has raised edge when inflammed which contain vesicles & crust not seen HD.Lesion is usually itchy & not anaesthetic.

• Granuloma multiforme- characterised by cincinate lesions of varying size,lesions have infiltrated border,No hypopigmentation,normal sweat & hair growth.

• Seborrheic dermatitis-occurs mostly in children.Presents as dry scaly,hypopigmented macules affecting the cheeks,alae nasi,eyebrow,hair line & scalp.lesions show no anaesthesia.

• Sarcoidosis-can present with macules,papules,nodules & may be difficult to differentiate from tuberculoid leprosy.Lesion are not anaesthetic,there are signs & symptoms of systemic disease.pt may have erythema nodosum & kveim test is positive


Differential diagnosis

• Cutaneous tuberculosis-(lupus vulgaris)-characterised by extensive tissue destruction, presence of scar tissue.lesion show sign of healing from one end & extension at the other end.

• Cutaneous leishmaniasis• Kaposi sarcoma-lesion are usually purplish,highly vascular

& easily bleeds,usually associated with lymphedema.patient have evidence of immunosupppression.

• Other condition-molluscum contagiosum,neurofibromatosis,blastomycosis.


Differential diagnosis of HD

• Conditions causing thickened nerves• Peroneal muscular dystrophy(Charcot Mary

tooth disaese• Amyloidosis• Refsum’s disease• Dejerine Sotter’s disease


Differential diagnosis of hansen’s disease

• Disease presenting with clawing of the digit• Dupuytren’s contracture-starts with 4th finger 1st .• Congenital flexion deformity-5th finger usually.• Tertiary yaws-affects 3rd ,4th & 5th fingers.• Diseases presenting with plantar ulcers• Syringomyelia• Diabetic neuropathy• Hereditary sensory neuropathy


Differential diagnosis of leprosy`

• Ectropion,entropion,trichiasis-commonly due to trauchoma.

• Iridocyclitis-onchocercaisis,connective tissue disease,tuberculosis.


Differential diagnosis of hansen’s disease

• Conditions causing anaesthetic limb/patch• Traumatic nerve damage• Tropical ataxic neuropathy-xt by

weakness,ataxia & optic neuropathy.• Syringomyelia-characterised by dissociated

anaesthesia,lower motor neuron sign in the upper limb & upper motor neuron sign in the lower limb.


Borderline tuberculoid



Borderline tuberculoid leprosy



WHO MDT regime for adults with HDType of leprosy Paucibacillary leprosy Multibacillary leprosy

Classification Indeterminate,tuberculoid,borderline tuberculoid

Borderline tuberculoid,borderline borderline,bordeline lepromatous,lepromatous

Regime Supervised Rifampicin 600mg monthly +Daily unsupervised dapsone 100mg

Supervised rifampicin 600mg monthly +Supervised clofazimine 300mg monthly +Daily unsupervised Dapsone 100mg &Daily unsupervised Clofazimine 50mg

Duration of treatment 6 months At least 1-2 years.


http://en.wikipedia.org/wiki/File:MDTRegimens.jpg


Principles of mgt & control of leprosy

• Adequate dissemination of information• Early diagnosis & appropriate management• Ensure availability of drug regimes used in

leprosy • Early & appropiate mangement of reactional

states• Adequate supportive measures

http://en.wikipedia.org/wiki/File:MDTRegimens.jpg


O no! Too late for MDT to salvage!florid leprosy deformities.


THANKS FOR YOURTIME

& ATTENTION.

BEST OF LUCK IN YOUR EXAMS.

Classification & Clinical Features of Leprosy

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