Pinta is a
contagious, mild, systemic, nonvenereal treponematosis caused by
Treponema carateum, which is morphologically identical to Treponema
pallidum.
The disease
occus in the Caribbean area, Central America and parts of remote, arid
inland regions and river valleys of the Tropical South America.
Mode of
transmission:
Transmission, usually after long intimate contact, is by skin-to-skin
inoculation.
Clinical
presentation:
Image1 ;
Image2 .
The lesions of
pinta are confined to the skin and become very extensive. These are
usually located on the extremities.
There is often
overlap between the three clinical stages. Initial lesions are
erythematous maculopapules, which grow by peripheral extension and
often coalesce.
The secondary
lesions are widespread, long-lasting scaly plaques that show a
striking variety of colours - red, pink, slate blue and purple.
These lesions
merge with the late stage, in which depigmentation resembling vitiligo
occurs, and sometimes there is epidermal atrophy.
Microscopic features: Primary
and secondary lesions are identical and show hyperkeratosis,
parakeratosis and acanthosis.
There is
exocytosis of inflammatory cells, sometimes with intraepidermal
abscesses.
Hypochromic
areas show loss of basal pigmentation with numerous melanophages in
the upper dermis.
The
dermal infiltrate, like the other changes, is heavier in established
than in early lesions and includes lymphocytes, plasma cells and
sometimes neutrophils. The infiltrate is predominantly superficial and
perivascular.
The treponemes
can be demonstrated by silver methods - they are present mainly in the
upper epidermis and are rarely found in the dermis.
Darkfield
examination of exudate and serologic tests for syphilis are positive
when the secondary lesions appear.
A single dose
of long-acting penicillin is curative.
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