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.
plexusA network of interwoven nerves
or blood vessels..
plicationA 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 syndromeDifficul-
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.
plutoniumA radioactive metallic ele-
ment which occurs naturally only in
uraniumores; it is produced artificially
in breeder reactors.
PMSThe abbreviation for premenstrual
syndrome.
PMTThe abbreviation for premenstrual
tension (an alternative name for pre-
menstrual syndrome).
pneumaturiaThe presence of gas in
the urine, usually indicating that a fis-
tulahas developed between the bladder
and the intestine.
pneumo-A prefix meaning related to
the lungs, to air, or to the breath.
pneumococcusA common name for
STREPTOCOCCUS PNEUMONIAE(see Strep-
tococcal infections).
pneumoconiosisAny 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-raybefore symptoms develop.
The main symptom is shortness of
breath. In severe cases, cor pulmonaleor emphysemamay develop. The risk of
tuberculosisor lung canceris 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 pneumoniaAn 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 ofantibiotic 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.
pneumonectomySurgery carried out to
remove a lung.
pneumoniaInflammation 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-
MONIAE, HAEMOPHILUS INFLUENZAE, and
STAPHYLOCOCCUS AUREUS. Symptoms are
usually fever, chills, shortness of breath,
and a cough that produces yellow-green
sputumand 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 drugsor antifun-
gal drugs. Aspirin or paracetamolmay
be given to reduce fever, and, in severe
cases, oxygen therapy and artificial ven-
tilationmay be needed. In most cases,
recovery usually occurs within 2 weeks.PLEXUS PNEUMONIAP