Transcript Leprosy - doc meg's hideout

Leprosy
Dr. Meg-angela Christi Amores
Leprosy
• A.k.a. Hansen’s Disease
• nonfatal, chronic infectious disease caused by
Mycobacterium leprae
• clinical manifestations are largely confined to
the skin, peripheral nervous system, upper
respiratory tract, eyes, and testes
Etiology
• Mycobacterium leprae
– obligate intracellular bacillus
– confined to humans, armadillos in certain locales,
and sphagnum moss
– Acid fast; ideally detected in tissue sections by a
modified Fite stain
– almost exclusively a disease of the developing
world
– associated with poverty and rural residence
Transmission
• Remains uncertain
• Nasal droplet infection, contact with infected
soil, and even insect vectors have been
considered the prime candidates
• bedbugs and mosquitoes
• ~50% of leprosy patients have a history of
intimate contact with an infected person
Disease Spectrum
• Incubation period: between 2 and 40 years,
although it is generally 5–7 years
• polar tuberculoid (TT)
• borderline tuberculoid (BT)
• mid-borderline (BB, which is rarely
encountered)
• borderline lepromatous (BL)
• polar lepromatous (LL)
• Tuberculoid Leprosy
• symptoms confined to the
skin and peripheral nerves
• consist of one or a few
hypopigmented macules or
plaques
• sharply demarcated and
hypesthetic, often have
erythematous or raised
borders,
• devoid of the normal skin
organs (sweat glands and hair
follicles)
• dry, scaly, and anhidrotic.
• Tuberculoid Leprosy
• asymmetric enlargement of
one or a few peripheral
nerves
• most commonly affected are
the ulnar, posterior auricular,
peroneal, and posterior tibial
nerves, with associated
hypesthesia and myopathy
• Lepromatous Leprosy
• symmetrically distributed skin
nodules , raised plaques, or
diffuse dermal infiltration,
which, when on the face,
results in leonine facies
• loss of eyebrows and
eyelashes, pendulous
earlobes, and dry scaling skin,
particularly on the feet
• acral, distal, symmetric
peripheral neuropathy and a
tendency toward symmetric
nerve-trunk enlargement
• Lepromatous Leprosy
• bacilli are numerous in the
skin (as many as 109/g),
where they are often found in
large clumps (globi), and in
peripheral nerves
• bacilli are plentiful in
circulating blood and in all
organ systems except the
lungs and the central nervous
system
• nerve enlargement and
damage tend to be symmetric
Complications
• Extremities
– primarily a consequence of neuropathy leading to
insensitivity and myopathy
– affects fine touch, pain, and heat receptors but
generally spares position and vibration
appreciation
– ulnar nerve
• clawing of the fourth and fifth fingers
• loss of sensation
– loss of distal digits in leprosy is a consequence of
insensitivity, trauma, secondary infection
Complications
• Nose
– chronic nasal congestion and
epistaxis
– destruction of the nasal cartilage,
with consequent saddle-nose
deformity or anosmia
• Eye
– lagophthalmos and corneal
insensitivity
– uveitis, with consequent cataracts
and glaucoma
Complications
• Testes
– mild to severe testicular dysfunction
– decreased testosterone, and aspermia or
hypospermia
– impotent and infertile
• Amyloidosis
• Nerve Abscesses
– cellulitic appearance of the skin
– affected nerve is swollen and exquisitely tender
Diagnosis
– characteristic skin lesions and skin histopathology
– associated with diffuse hyperglobulinemia, which
may result in false-positive serologic tests (e.g.,
VDRL, RA, ANA)
Treatment
• dapsone (50–100 mg/d), clofazimine (50–100
mg/d, 100 mg three times weekly, or 300 mg
monthly), and rifampin (600 mg daily or
monthly)
Prevention and Control
• Vaccination at birth with bacille CalmetteGuérin (BCG) has proved variably effective in
preventing leprosy