Animals P by: Geoffrey LaPage Published by ... - PSSurvival.com

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Animals Parasitic in Man
M. It is still, however, necessary to keep a watch lest the infection
return again.
When the host exposes its skin to the soil containing the
third infective larvae, these larvae bore their way through the
skin. Often they enter the softer skin between the toes, or
through the skin sf the ankles, or, when the soil gets on to the
hands, through the skin of the hands or wrists. As they bore
into the skin they cause intense itching and also inflammation,
the signs of which are reddening of the skin and some swelling
under it. A rash of small papules often develops and these become
small vesicles. All this is the expression of the host’s
reaction against these invaders of its body and the skin-eruption
caused is calledground-itch. If the vesicles become infected
with bacteria, as they may do if the infected person scratches
them to allay the itching, unpleasant sores may develop.
A similar eruption in the skin of man may be caused by the
larvae of certain strains of Ancylostoma braziliense. The normal
hosts of this species are dogs and cats, but the larvae of certain
strains of it may penetrate into the skin of man. The larvae of
these strains only rarely develop in man into the adult hookworms,
but they can penetrate into human skin and, when they
do this, they may live for a time in the skin and move about in
it, causing as they do so; a skin-eruption similar to grounditch,
which is called creeping e+don, or cutaneous larva migrans,
because the eruption follows the migration of the larvae in the
skin. Cutaneous larva migrans may also be caused by the
larvae of several other species which are normally not parasitic
in man. These larvae, when they get into the skin of man,
cannot grow up into adults and sooner or later they die in
human ski and their remains are absorbed. Among the
species whose larvae cause skin irritation in this way are the
hookworms of dogs and cattle and the bot-flies of horses.
Cutaneous larva migrans must be clearly distinguished from
visceral larva m&raw, described on p. 6%
A similar eruption of the skin may be caused by the larvae
of another roundworm, Gnathostoma spinigerum, the adults of
which live in tunnels that they cause in the stomachs of cats
and their wild relatives and also in the stomachs of dogs. The
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