CHOCOLATE CYST
TYPES
Two main species of chlamydiae cause
disease in humans. They can be treated
with
antibiotic drugs
.
The first species, C
hlamydia trachomatis,
is responsible for some sexually trans-
mitted infections, including about half
of all cases of
nongonococcal urethritis
in
men and
pelvic inflammatory disease
in
women. It can also cause the tropical
eye disease
trachoma
.
A second species, C
hlamydia psittaci
, is
responsible for
psittacosis
.
This is a rare
form of pneumonia that is transmitted
to humans from birds.
Chlamydia is also responsible for a type
of pneumonia (see
Chlamydia pneumoniae
) .
Chlamydia pneumoniae
An infectious organism that can cause a
m ild form of
pneumonia
,
w hich occurs
particularly in young adults.
Chlamydia psittaci
An organism that mainly affects birds
but can occasionally spread to people
who are in contact with pigeons, par-
rots, parakeets, or poultry. It causes a
type of pneumonia called
psittacosis
.
Chlamydia trachomatis
An organism that belongs to the chla-
mydiae group and has several strains. In
men, it is a major cause of the sexually
transmitted infection
nongonococcal ure-
thritis
,
w hich may cause a discharge
from the penis. In women, the infec-
tion usually causes no symptoms, but
can lead to
pelvic inflammatory disease
and possibly
salpingitis
(inflammation
of the fallopian tubes). A baby born to
a woman w ith chlamydial infection
may
acquire
an
acute
eye
disorder
called neonatal
ophthalmia
.
In some parts of Africa and Asia, cer-
tain
strains
of C
hlamydia
trachomatis
cause
trachoma
,
a serious eye disease
that is the most
common cause of
blindness worldwide.
chloasma
A skin condition, also called melasma,
in which blotches of pale brown pig-
mentation appear on the face, notably
on the forehead, nose, and cheeks. The
condition is aggravated by sunlight.
Chloasma sometimes develops during
pregnancy. More rarely, it is associated
with the menopause or the use of
oral
contraceptives
.
The areas of abnormal
pigmentation usually fade in time, but
the condition may recur.
chloral hydrate
A type of
sleeping drug.
chlorambucil
An
anticancer drug
that is used in the
treatment of some types of cancer, such
as
Hodgkin’s disease.
chloramphenicol
An
antibiotic drug
commonly used as
drops to treat superficial eye infections.
Chloramphenicol is also used to treat
life-threatening infections of unknown
cause. Rarely, tablets or injections are
associated with aplastic
anaemia.
chlorate poisoning
The toxic effects of chemicals called
chlorates, which are present in some
defoliant weedkillers.
Symptoms of chlorate poisoning in -
clude
ulcers
the
mouth,
abdominal
pain, and diarrhoea. Chlorates can also
cause kidney and liver damage, corro-
sion of the intestines, and
methaemo-
globinaemia
(a harmful chemical change
in the blood
pigment
haemoglobin
).
Even small doses can be fatal; medical
help is needed immediately if chlorate
poisoning is suspected.
chlordiazepoxide
A
benzodiazepine drug
mainly used in
the treatment of
anxiety.
chlorhexidine
A type of disinfectant mainly used to
cleanse
the
skin
before
surgery
or
before taking a blood sample.
chlorine
A poisonous, yellowish-green gas with
powerful
bleaching
and
disinfectant
properties. If inhaled in even very small
amounts, chlorine gas is highly irritat-
ing to the lungs; inhalation of large
amounts is rapidly fatal.
chlorofluorocarbon propellants
Aerosol propellants, commonly known
as CFCs, that contain compounds of
gases such as carbon, chlorine, fluorine,
and hydrogen. CFCs have contributed
to the damage to the ozone layer.
chloroform
A colourless liquid producing a vapour
that was formerly used as a general
anaesthetic
(see
anaesthesia, general).
However, chloroform is associated with
liver damage and heart problems and
safer drugs are now used instead.
Chloromycetin
A brand name for the antibiotic drug
chloramphenicol
,
w hich is often used in
eye and ear preparations.
chloroquine
A drug used mainly in the prevention
and treatment of
malaria.
It is also used
as an
antirheumatic drug
to treat
rheuma-
toid arthritis
and
lupus erythematosus
.
Possible side effects of chloroquine
include nausea, headache, diarrhoea,
rashes, and abdominal pain. Long-term
use may damage the retina of the eye.
chlorphenamine
An
antihistamine drug
that is used to
treat a number of allergic conditions
such as allergic
rhinitis
(hay fever),
allergic
conjunctivitis
,
angioedema
(aller-
gic facial swelling) and
urticaria
(nettle
rash). Chlorphenamine is also a com-
ponent of some
cold remedies
.
chlorpheniramine
An alternative name for
chlorphenamine
.
chlorpromazine
A widely prescribed
antipsychotic drug
used to relieve symptoms of major psy-
chotic illnesses such as
schizophrenia
and
mania
.
The drug reduces delusional
and hallucinatory experiences and may
have an effect on irritability and overac-
tivity. It is also used as an
antiemetic drug
to treat nausea and vomiting, especially
when these problems are the result of
treatment with other drugs, radiother-
apy, or anaesthesia.
Chlorpromazine may cause
photosen-
sitivity
(increased sensitivity of the skin
to sunlight) and, in some cases,
parkin-
sonism
(a movement disorder), slow
reactions, and blurred vision.
chlorpropamide
A drug that is used to treat
diabetes mel-
litus
(see
hypoglycaemics, oral
) .
choanal atresia
A
congenital
abnormality of the
nose
in
which one or both of the nasal cavities
are not fully developed.
chocolate cyst
A brown swelling in an
ovary
.
Chocolate
cysts may develop in
endometriosis
,
a
condition in which endometrial tissue
(w hich forms the lining of the uterus)
is found in sites outside the uterus. The
colour is the result of clotted blood
within the cysts.
C
167
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