CAVERNOUS SINUS THROMBOSIS
SYMPTOMS
The main symptom, appearing three to
ten days after the bite or scratch, is a
swollen
lymph node
near the affected
area. The node may become painful and
tender, and an infected blister
may
develop at the site of the injury. A fever,
rash, and headache may occur.
DIAGNOSIS AND TREATMENT
Diagnosis of cat-scratch fever is con-
firmed by
biopsy
(removal of a small
sample of tissue for microscopic analy-
sis) of the swollen lymph node and by a
skin
test.
Analgesic drugs
(painkillers)
may be used to relieve the fever and
headache. In most cases, the illness clears
up completely within two months.
cats, diseases from
Cats carry various parasites and infec-
tious organisms that can be spread to
humans. Some of these are specific to
cats; others may also affect dogs.
SPECIFIC DISEASES
The most serious disease that can be
contracted from an infected cat is
rab-
ies
.
Anyone who is bitten by a cat (or
any other animal) in a country where
rabies is present should seek medical
advice without delay.
Cat-scratch fever
is an uncommon ill-
ness that is caused by infection with
the bacterium B
artonella
henselae
fol-
lowing a scratch or bite from a cat.
Cats commonly carry the
protozoan
(single-celled parasite) T
oxoplasma gondii,
w hich causes the disease
toxoplasmosis
.
Infection with the parasite, w hich is
usually from contact with a cat’s faeces,
is not generally serious, but it can have
severe
effects
in
pregnant
women.
Infections in early pregnancy can lead
to
miscarriage
or severe malformation of
the fetus. Later in pregnancy, infections
can result in nervous system disorders
in the fetus and may even lead to blind-
ness in early childhood.
Cat faeces may also carry eggs of the
cat roundworm, a possible cause of
toxocariasis
.
Rarely,
a larva
from
an
ingested roundworm egg migrates to
and lodges in an eye, causing deteriora-
tion of vision or blindness. Children
who have been playing in sand or soil
that has been contaminated by cat fae-
ces are at risk of coming into contact
with the worm eggs.
Other cat-related disorders in humans
include
tinea
(fungal infections of the
skin, hair, or nails), particularly ring-
worm, (ringlike fungal patches, often
on the scalp), bites from cat fleas, and
allergic reactions to dander (scales from
animal skin, hair, or feathers) that may
cause
asthma
or
urticaria
(nettle rash).
PREVENTION
Diseases from cats can be avoided by
good hygiene, such as hand-washing,
particularly after touching a cat. All pets
should have regular worm ing and flea
treatment and veterinary care if ill.
cauda equina
A “spray’’ of nerve roots resembling a
horse’s
tail
that
descends
from
the
lower
spinal cord
and occupies the lower
third of the spinal canal.
caudal
This word is used to refer to the lower
end of the
spine
.
The word “caudal”
means “of the tail” .
caudal block
A type of
nerve block
in w hich a local
anaesthetic is injected into the lower
part of the spinal canal (the central
space w ithin the spine). Caudal block
may be used to anaesthetize the but-
tocks and genitals as part of
obstetric
and gynaecological procedures.
cauliflower ear
Painful, swollen distortion of the pinna
(ear flap) resulting from blows or fric-
tion that have caused bleeding in the
soft
cartilage
of the ear.
Immediate treatment following an
injury involves the use of ice-packs to
reduce the swelling. In severe cases, a
doctor may drain blood from the ear
and apply a pressure bandage.
A f f e c t e d
a r e a
Example of
cauliflower ear
Following injuryto
the ear, there has
been bleeding into
the soft cartilage.
The ear flap has
been deformed, with
loss ofthe normal
folds of skin.
causalgia
A persistent, burning pain, usually in
an arm or leg. Causalgia most often
occurs as a result of injury to a nerve
by a deep cut, lim b
fracture
,
or gunshot
wound. The skin overlying the painful
area may be red and tender, or blue,
cold, and clammy. The condition may
be aggravated by light sensations, such
as touch, or by emotional factors.
In some cases, treatment with
antide-
pressant drugs
or
anticonvulsant drugs
is
effective. A few people benefit from
sympathectomy
,
in w hich nerves supply-
ing the affected area are severed.
caustic
Describes substances that have a burn-
ing or corrosive action on body tissues
or a burning taste. An example is caus-
tic soda, the common name for sodium
hydroxide. Caustic agents such as silver
nitrate are used to destroy warts.
cauterization
The application of a heated instrument
to destroy tissues, stop bleeding, or pro-
mote healing. Cauterization may be used
to treat conditions such as
haemorrhoids
(piles) and
cervical erosion.
It has been
largely replaced by
electrocoagulation
(use
of high-frequency electric current and,
increasingly, laser to seal blood vessels).
Caverject preparations
A brand name for preparations of
alpros-
tadil
,
a
prostaglandin drug
used to treat
impotence, normally by self-injection.
cavernous sinus thrombosis
Blockage of a venous
sinus
(a channel
for venous blood located deep inside
the skull behind an eye socket) by a
thrombus
(an
abnormal
blood
clot).
Cavernous sinus thrombosis is usually a
complication of a bacterial infection in
an area drained by the veins entering
the sinus. At first, only the veins behind
one eye are affected, but w ithin a few
days the thrombosis may spread to the
sinus behind the other eye.
CAUSES
Among the infections that can lead to
cavernous sinus thrombosis are
cellulitis
(a severe skin infection) of the face,
infections of the mouth, eye, or middle
ear,
sinusitis
(infection of the air spaces
of the facial skull),
and
septicaemia
(infection in the bloodstream).
SYMPTOMS
Symptoms of cavernous sinus thrombo-
sis include severe headache, high fever,
pain and loss of sensation in and above
the affected eye due to the pressure on
the fifth cranial nerve, and
proptosis
(protrusion of the eyeball) due to swel-
ling around and behind the eye. In
some cases, vision may become blurred
C
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