cancrum orisSee noma.
candidiasisInfection by the fungus
CANDIDA ALBICANS, also known as thrush
or moniliasis. Candidiasis affects areas
of mucous membrane in the body, most
commonly the vagina and the inside of
the mouth. In infants, it can occur in
conjunction with nappy rash.
The fungus is normally present in the
mouth and vagina but may multiply
excessively if antibiotic drugsdestroy the
harmless bacteria that control its growth,
or if the body’s resistance to infection is
lowered. Certain disorders, notably dia-
betes mellitus, and hormonal changes due
to pregnancy or oral contraceptives, may
also encourage its growth. Candidiasis
can be contracted by sexual intercourse
with an infected partner. The infection is
far more common in women than in men.
Symptoms of vaginal infection include a
thick, white discharge, genital irritation,
and discomfort when passing urine. Less
commonly,the penis is infected in men,
usually causing balanitis. Oral candidia-
sis produces sore, creamy-yellow, raised
patches in the mouth. Candidiasis may
spread to other moist areas of the body
and may also affect the gastrointestinal
tract, particularly in people with im-
paired immune systems. Treatment for
candidiasis is with topical preparations
such as creams, pessaries, or lozenges,
or with oral antifungal drugs.
canine tooth See teeth.
cannabisPreparations that are derived
from the hemp plant CANNABIS SATIVA,
which produce euphoria and hallucina-
tions (see marijuana).
cannulaA smooth, blunt-ended tube
inserted into a blood vessel, lymphatic
vessel, or body cavity, in order to intro-
duce or withdraw fluids. Cannulas are
used for blood transfusionsand intra-
venous infusionsand for draining pleural
effusions. They may be left in place for
several days if continuous testing of, or
introduction of, fluids is required.
cap, cervical A flexible contraceptive
device placed directly over the cervixto
preventsperm from entering (see con-
traception, barrier methods of).
Capgras’ syndromeThe delusion that
a relative or friend has been replaced by
an identical impostor. Also known as theare harboured by animals and can be
passed to humans in contaminated food,
especially poultry, causing food poison-
ing. The bacteria also cause a form of
the inflammatory colon disease colitis.
cancerA group of diseases character-
ized by the abnormal and unrestrained
growth of cells in body organs or tissues.
Tumour-forming cells develop when the
oncogenes(genes controlling cell growth
and multiplication) in a cell or cells
undergo a series of changes. A small
group of abnormal cells develop that
divide more rapidly than normal, lack
differentiation (they no longer perform
their specialized task), and may escape
the normal control of hormones and
nerves. Cancers differ from benign neo-
plasms(abnormal growths, such as warts)
in that they spread and infiltrate sur-
rounding tissue and may cause blockages,
destroy nerves, and erode bone. Cancer
cells may also spread via the blood ves-
sels and lymphatic system to form
secondary tumours (see metastasis).
Causes of cancer include environmen-
tal factors such as sunlight, smoking,
pollutants, alcohol consumption, and
dietary factors. These factors may pro-
voke critical changes in body cells in
susceptible people. Susceptibility to cer-
tain cancers may be inherited.
Many cancers are now curable, usually
by combinations of surgery, radiothera-
py,and anticancer drugs. For information
on particular cancers, refer to the organ
in question (for examplelung cancer;
stomach cancer).
cancerphobiaAn intense fear of devel-
oping cancer, out of proportion to the
actual risk, that significantly affects the
sufferer’s life. Patterns of behaviour typ-
ical of obsessive–compulsive disorder(for
example, prolonged washing rituals)
may be adopted in an attempt to reduce
the risk of cancer. Psychotherapyinclud-
ing behaviour therapymay be of benefit.
cancer screeningTests to detect early
signs of cancer in groups of people who
are susceptible to cancer because of
their age, occupation, lifestyle, or genetic
predisposition. Tests for cancers of the
cervix (see cervical smear test), breast
(see mammography), bladder, and colon
have proven to be effective.CANCER CAPGRAS’ SYNDROMEC