drug used in the
due to impaired blood supply to heart
muscle), certain types of
(irregularity of the heartbeat), and to
control symptoms of
(overactivity of the thyroid gland). Pos-
sible adverse effects are typical of other
n a e v u s
A type of skin blemish of which
there are 2 main groups: pigmented
naevi are caused by abnormality or
overactivity of melanocytes (skin cells
that produce the pigment
cular naevi are caused by an abnormal
collection of blood vessels.
The most common types of pigmented
flat brown areas that may occur
where the skin is exposed to the sun.
Another common type is a mole, some-
times called a melanocytic naevus. In
rare cases, moles become cancerous
red-brown naevi that occur in childhood.
Blue naevi are common in young girls.
Most black and Asian infants are born
with blue-black spots on their lower
Mongolian blue spot
Port-wine stains and strawberry marks
examples of vascular naevi.
Most naevi are harmless. However, if a
naevus suddenly appears, grows, bleeds,
or changes colour, medical advice should
be sought immediately to exclude the
A hard, curved plate on the fingers
and toes composed of
protein). Nails grow from an area called
the nail bed. At the base of each nail a
half-moon shape, the lunula, is crossed
by a flap of skin called the cuticle. The
surrounding skin is known as the nail
fold. A fingernail takes about
to grow from base to tip; toenails take
twice as long.
The nails are susceptible to damage
through injury, or by bacterial or fungal
. Sometimes they become abnormally
thick and curved: a condition known as
Nail abnormalities may
be a sign of skin disease, such as
, or of more generalized disease,
for example iron-deficiency
usual nail colour may indicate disease.
Treatment of nail disorders can be
difficult. Creams and lotions seldom
penetrate sufficiently; oral medication
may take months to be effective.
STRUCTURE OF NAIL
n ail-bitin g A common habit in children
during their early years at school. Most
children grow out of it, although nail-
biting sometimes continues as a nervous
habit in adolescents and adults.
Various preparations with an unpleas-
ant taste can be painted on the nails as
a preventive measure.
An antibiotic drug used
to treat and/or to prevent
. Possible adverse effects include
nausea, vomiting, increased sensitivity
to sunlight, blurred vision, drowsiness,
A drug that blocks the action
Naloxone reverses the
breathing difficulty caused by high doses
of opioid drugs given during surgery.
The drug is also given to newborn babies
who are affected by opioid drugs used to
relieve the mother's pain during labour.