ERYTHEMATOUS
E
may occur as a reaction to some drugs,
particularly
sulphonamide drugs
,
penicillin
drugs
,
and
salicylate drugs
.
Sometimes
there is no apparent cause.
SYMPTOMS
The swellings, w hich may range from
1
to
10
cm in diameter, are shiny and
tender and occur on the fronts of the
shins, the thighs, and, less commonly,
the arms. Joint and muscle pains and
fever also usually occur.
TREATMENT
Successful treatment of any underlying
condition clears the swellings. Bed rest,
analgesic drugs
(painkillers), and, occa-
sionally,
corticosteroid drugs
may also be
necessary The condition usually sub-
sides w ithin about a month.
erythematous
Characterized by
erythema
(redness of
the skin).
erythrasma
A bacterial skin infection, caused by the
organism C
orynebacterium
, that affects
the groin, armpits, and skin between
the toes. Raised, irregularly shaped, dis-
coloured patches appear in the affected
areas. Erythrasma is most common in
people who have
diabetes mellitus
.
The
condition generally clears up following
a course of treatment with the antibiot-
ic drug
erythromycin
.
erythrocyte
Another name for a
red blood cell
.
erythroderma
See
exfoliative dermatitis
.
erythrogenic toxin
A poisonous protein produced by strep-
tococcal bacteria that causes the red
rash in
scarlet fever
.
erythromelalgia
A rare condition, also known as Ger-
hardt-M itchell disease, that principally
affects the
extremities
of the body,
most commonly the feet. Erythrome-
lalgia usually first appears in middle
age. It may be associated w ith
poly-
cythaemia
(an increase in the total red
cell mass of the blood),
thrombocytosis
(an increase in the number of
platelets
in the blood),
gout
(a metabolic disor-
der that causes attacks of arthritis), and
neurological disease.
Erythromelalgia is characterized by
severe attacks of burning pain and mot-
tled redness of the skin; it may be
triggered by heat. Attacks of the condi-
tion can be relieved by elevating the
affected lim b and applying something
cold, such as an ice pack, to it. No spe-
cific treatment is available, but
aspirin
may relieve the condition in some cases.
erythromelia
Diffuse
erythema
(redness) and
atrophy
(wasting) of the skin of the lower limbs.
The cause of erythromelia is unknown.
erythromycin
An
antibiotic drug
used in the treatment
of skin, chest, throat, and ear infections.
Erythromycin is given to people with
these conditions who are allergic to
penicillin drugs
.
In addition, it is particu-
larly useful in the treatment of
pertussis
(whooping cough) and
legionnaires’ dis-
ease
.
The drug may be taken in tablet
form,
liquid form,
or
intravenously
Possible adverse effects include nausea,
diarrhoea, and an itchy rash.
erythrovirus
A
virus
formerly known as parvovirus.
Infection with a strain of erythrovirus
causes
fifth disease
in humans.
escape beat
An automatic
heartbeat
that occurs after
an abnormally long pause in the heart
rhythm. An escape beat is therefore a
delayed beat that terminates a longer
cycle than normal.
eschar
A
scab
that forms on the surface of
skin that has been subject to damage,
for example by a
burn
.
Escherichia coli (E.coli)
A bacterium (see
bacteria
)
that is nor-
mally found in the intestines but can
cause illness under some circumstances.
Types of E.
coli
are often the cause of
traveller’s diarrhoea, w hich is usually a
m ild illness. Bacteria that enter the
bladder through the urethra are a com-
mon cause of
urinary tract infections
.
Some strains of E.
coli
, however, can
cause
serious
food-borne
infections
that may result in
haemolytic-uraemic
syndrome
(a condition in w hich red
blood cells are destroyed and kidney
function becomes impaired).
Esmarch’s bandage
A
broad
rubber
bandage
that
is
wrapped around the elevated limb of a
patient to force blood out of the blood
vessels towards the heart. This action
creates a blood-free area, so surgery on
the limb can be performed more easily.
The
patient
is
anaesthetized
(see
anaesthesia
) ,
then the Esmarch’s ban-
dage is wrapped from the fingers or
toes upwards. An inflatable tourniquet
(a device used to compress blood ves-
sels) is then applied to the upper arm or
thigh to stop blood from returning to
the limb. The
Esmarch’s
bandage is
removed, leaving the inflated tourni-
quet in position during surgery.
esotropia
An alternative term for a convergent
squint
,
in w hich one eye looks directly
at an object while the other eye turns
inwards. (See also
exotropia
. )
ESR
The abbreviation for erythrocyte sedi-
mentation rate, w hich is the rate at
w hich erythrocytes
(
red blood cells
)
sink
to the bottom of a test tube.
WHY IT
IS DONE
The ESR is increased if the level of
fibrinogen
(a type of protein) in the
blood is raised. Fibrinogen is raised in
response to a range of illnesses, includ-
ing
inflammation
,
especially when this
is caused by infection or by an
auto-
immune
disease
.
The
ESR
is
also
increased if levels of
antibodies
(proteins
manufactured by the immune system)
are very high, as occurs in
multiple
myeloma
.
ESR is therefore useful for
helping to diagnose these conditions as
well as in monitoring their treatment.
HOW
IT
IS DONE
Whole blood collected from the patient
is mixed with anticoagulant (a chemical
that prevents the blood from clotting)
in a test tube. In one method, the blood
is left undisturbed at a constant temper-
ature for one hour. The red blood cells,
w hich can be seen as a dark red clump,
settle to the bottom of the tube, leaving
the clear, straw-coloured plasma at the
top. The ESR is the number of m illi-
metres the red cells fall in one hour.
essential amino acids
The nine
amino acids
required for pro-
tein synthesis,
growth,
and develop-
ment, that cannot be made by the body
and must be obtained in the diet.
essential fatty acids
The
fatty acids
that cannot be synthe-
sized by the body and must therefore be
obtained in the diet.
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