URTICARIA, NEONATAL
UTERUS, CANCER OF
of urticaria in which weals form after
the skin is stroked. Urticaria sometimes
occurs with
angioedema.
The cause of urticaria is often un-
known. The most common known cause
is an allergic reaction (see
allerg
5
/),
often to a particular food, food additive,
or drug. Urticaria may also be caused by
exposure to heat, cold, or sunlight. Less
commonly, it may be associated with
another disorder, such as
vasculitis, sys-
temic lupus erythematosus,
or
cancer.
Itching can be relieved by applying
calamine lotion
or by taking
antihis-
tamine drugs.
More severe cases may
require
corticosteroid drugs.
Identifying
and avoiding known trigger factors can
help prevent future reactions. A tend-
ency to urticaria often disappears in
time without treatment.
u r t i c a r i a , n e o n a ta l
A very common,
harmless skin condition, also known as
erythema neonatorum or toxic eryth-
ema, that affects newborn infants. A
blotchy rash, in which raised white or
yellow lumps are surrounded by ill-
defined
red areas of inflammation,
forms, mainly affecting the face, chest,
arms, and thighs. The cause of neonatal
urticaria is unknown. The rash usually
clears up without treatment.
u te r in e m u s c le r e l a x a n t s
Drugs that
are used to delay the premature del-
ivery of a
fetus.
Beta2~adrenoceptor
stimulants, such as
salbutamol,
relax
the muscle of the
uterus
and may post-
pone labour for days or weeks in at-risk
pregnancies of 24-33 weeks' gestation.
Delay of premature labour for up to 48
hours allows time for
corticosteroid
drugs
to be given to the mother to help
the fetal lungs to mature.
u te r o v a g in a l
p r o la p s e
See
uterus,
prolapse of.
u te r u s
The hollow, muscular organ of
the female reproductive system in which
the fertilized
ovum
(egg) normally be-
comes embedded and in which the
embryo
and
fetus
develop. The uterus
is commonly known as the womb. It is
situated in the pelvic cavity, behind the
bladder
and in front of the intestines.
In a nonpregnant woman, the uterus
is 7.5-10 cm long and weighs 60-90 g.
The lower part opens into the
vagina
at
UTERUS
the
cervix;
the upper part opens into the
fallopian tubes.
The inside is lined with
endometrium.
The uterus expands in size
during pregnancy to accommodate the
growing baby. At full-term, the powerful
uterine muscles expel the baby via the
birth canal (see
childbirth).
After the
menopause,
the endometrium atrophies
(becomes thinner) and the uterine mus-
cle and connective tissue are reduced.
Conditions that affect the uterus include
congenital
disorders, such as malform-
ation or absence of the uterus; tumours,
including
polysps, fibroids,
and cancer
of the endometrium (see
uterus
,
cancer
of);
infections, causing
endometritis;
and
hormonal disorders. (See also
uterus
,
prolapse of; uterus
,
retroverted.)
u te r u s , c a n c e r o f
A malignant growth
in the tissues of the
uterus.
Cancer of
the uterus mainly affects the cervix (see
cervix
,
cancer of)
and
endometrium.
In
rare cases, the uterine muscle is affected
by a type of cancer called a leiomyosar-
coma. The term uterine cancer usually
refers to cancer of the endometrium.
Risk factors for endometrial cancer
include anything that may raise oestro-
gen levels in the body, such as
obesity,
a
history of failure to ovulate, or taking
oestrogen horm ones
long term if these
are not balanced with
progestogen drugs.
It is also more common in women who
have had few or no children.
Before the
menopause,
the first symp-
tom of cancer of the uterus may be
menorrhagia
or bleeding between per-
iods or after sexual intercourse; after
574
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