fluorosisMottling of the tooth enamel
caused by ingestion of excess fluoride
as the teethare formed. In severe cases,
the enamel develops brown stains. Such
cases occur mostly where the fluoride
level in water is far greater than the rec-
ommended level or when additional
fluoride supplements are taken.
fluorouracilAn anticancer drugused in
the treatment of cancers of the breast,
bladder, ovaries, and intestine.
fluoxetineA type of antidepressant drug.
flurazepamA type of benzodiazepine
drugused as a sleeping drug to treat
insomnia. The drug’s effects may persist
the following day; and prolonged use
may result in dependence.
flurbiprofenA nonsteroidal anti-inflam-
matory drugused particularly to ease
the symptoms of musculoskeletal disor-
ders such as rheumatoid arthritis.
flushReddening of the face, and some-
times the neck, caused by dilation of
the blood vessels near the skin surface.
Flushing may occur during feveror as a
result of embarrassment. Hot flushes
are common at the menopause.
foam, contraceptiveSee spermicides.
foetusAn alternative spelling for fetus.
folic acidA vitaminthat is essential for
the production of red blood cellsby the
bone marrow. Folic acid is contained in
a variety of foods, particularly liver and
raw vegetables; adequate amounts are
usually included in a normal diet.
During pregnancy, folic acid is imp-
ortant for fetal growth and in the
development of the nervous system and
formation of blood cells. The incidence
of neural tube defectsis reduced if
women take folic acid supplements for
a month before conception and during
the first 12 weeks of pregnancy.
Folic acid deficiency is a cause of
megaloblastic anaemia, which produces
symptoms such as headaches, fatigue,
and pallor. Deficiency can occur during
any serious illness or can be the result
of a nutritionally poor diet.
folie à deuxA French term that is used
to describe the unusual occurrence of
2 people sharing the same psychotic ill-
ness (see psychosis). Commonly, the
2 are closely related and share one or
more paranoid delusions. If the sufferers
are separated, one of them almost al-
ways quickly loses the symptoms, which
have been imposed by the dominant,
and genuinely psychotic, partner.
folk medicineAny form of medical treat-
ment that is based on popular tradition,
such as the charming of warts or the use
of copper bracelets to treat rheumatism.
follicleA small cavity in the body. For
example, a hairfollicle is a pit on the
skin surface from which hair grows.
follicle-stimulating hormoneA gon-
adotrophin hormonethat is produced
and secreted by the pituitary gland and
acts on the ovary or testes.
folliculitisInflammation of 1 or more
hair follicles as a result of a staphylo-
coccal infection. Folliculitis can occur
almost anywhere on the skin but com-
monly affects the neck, thighs, buttocks,
or armpits, causing a boil; it may also
affect the bearded area of the face, pro-
ducing pustules (see sycosis barbae).
Treatment is with antibiotic drugs.
fomitesInanimate objects, such as bed
linen, clothing, books, or a telephone
receiver, that are not harmful in them-
selves but may be capable of harbouring
harmful microorganisms or parasites and
thus convey an infection from one per-
son to another. Fomites mainly transmit
respiratory infections, such as influenza.
The singular form of the word is fomes.
fontanelleOne of the 2 membrane-
covered spaces between the bones of a
baby’s skull. At birth, the skull bones
are not yet fully fused, and 2 soft areas
can be felt through the scalp. These are
the anterior fontanelle, which is dia-
mond-shaped and usually closes up by
age 18 months,
and the posterior
fontanelle, which
is triangular and
closes up within
the first 2 months.
It is normal for the
fontanelles to be-
come tense and
bulge out when a
baby cries. Per-
sistent tension at
other times may
indicate an abnor-
mality, particularlyFLUOROSIS FONTANELLE
F
Anterior
fontanelleFONTANELLE