PLEXUS
PNEUMONIA
P
called Bornholm disease, it often occurs
in epidemics and usually affects chil-
dren. There is sudden severe pain in the
lower chest or upper abdomen, with
fever, sore throat, headache, and malaise.
The disease usually settles in 3-4 days
without treatment.
plexus A network of interwoven nerves
or blood vessels.
.
plication A surgical procedure in which
tucks are taken in the walls of a hollow
organ and then stitched to decrease the
size of the organ.
Plummer-Vinson syndrome Difficul-
ty in swallowing due to webs of tissue
forming across the upper
oesophagus.
The syndrome often occurs with severe
iron-deficiency
anaemia
and
affects
middle-aged women.
plutonium A radioactive metallic ele-
ment which occurs naturally only in
uranium
ores; it is produced artificially
in breeder reactors.
PMS The abbreviation for
premenstrual
syndrome.
PMT The abbreviation for premenstrual
tension (an alternative name for
pre-
menstrual syndrome).
pneumaturia The presence of gas in
the urine, usually indicating that a
fis-
tula
has developed between the bladder
and the intestine.
pneumo- A prefix meaning related to
the lungs, to air, or to the breath.
pneumococcus A common
name
for
streptococcus pneum oniae
(see
Strep-
tococcal infections).
pneumoconiosis Any of a group of
lung diseases caused by the inhalation
of certain mineral dusts. Only dust par-
ticles less than 0.005 mm across reach
the alveoli (air sacs) in the lungs. The
particles accumulate and may cause
thickening and scarring. The main types
of pneumoconiosis are asbestosis (see
asbestos-related
diseases), coal workers'
pneumoconiosis, and silicosis, caused
by silica dust. These diseases primarily
affect workers aged over 50. However,
the incidence is falling due to better
preventive measures.
Pneumoconiosis is often detected by
a
chest X-ray
before symptoms develop.
The main symptom is shortness of
breath. In severe cases,
cor pulmonale
or
emphysema
may develop. The risk of
tuberculosis
or
lung cancer
is increased
following asbestos or haematite expo-
sure. Diagnosis is based on a history of
exposure to dusts, chest X-rays, medi-
cal examination, and
pulmonary function
tests. There is no treatment apart from
treating any complications. Further expo-
sure to dust must be avoided.
pneumocystis pneumonia An infection
of the lungs caused by
Pneumocystis
carinii
,
a type of
protozoa.
Pneumocystis
pneumonia is an
opportunistic infection
that is dangerous only to people with im-
paired resistance to infection.
It is
particularly common in those with
AIDS.
Symptoms include fever, dry cough, and
shortness of breath lasting weeks to
months. Diagnosis is made by examina-
tion of sputum or a lung
biopsy
. High
doses of
antibiotic drugs
(commonly co-
trimoxazole) may eradicate the infec-
tion; they may also be used over the
long term to prevent infection in those
people at increased risk.
pneumonectomy Surgery carried out to
remove a lung.
pneumonia Inflammation of the lungs
due to infection. There are 2 main types:
lobar pneumonia and bronchopneu-
monia. Lobar pneumonia initially affects
1 lobe of a lung. In bronchopneumonia,
inflammation
initially
starts
in
the
bronchi and bronchioles (airways).
Pneumonia can be caused by any type
of microorganism, but most cases are
due to viruses, such as adenovirus, or
bacteria, such as
streptococcus pneu-
m oniae
,
HAEMOPHILUS INFLUENZAE
,
and
staphylococcus au reu s
.
Symptoms are
usually fever, chills, shortness of breath,
and a cough that produces yellow-green
sputum
and occasionally blood. Potential
complications include
pleural effusion
,
pleurisy
, and a lung
abscess
.
Diagnosis is made by physical exami-
nation,
chest X-ray,
and examining
sputum and blood for microorganisms.
Treatment depends on the cause, and
may include
antibiotic drugs
or
antifun-
gal drugs. Aspirin
or
paracetamol
may
be given to reduce fever, and, in severe
cases,
oxygen therapy
and artificial
ven-
tilation
may be needed. In most cases,
recovery usually occurs within
2
weeks.
454
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