Bma Illustrated Medical Dictionary

around the eyelids, and severe muscle
pains, which may last for several weeks.
Trichinosis may be suspected from the
symptoms, and the diagnosis is con-
firmed by blood tests, or by a muscle
biopsy. Treatment of the infestation is
with an anthelmintic drug.
trichomoniasisAn infection caused by
the protozoanTRICHOMONAS VAGINALIS.
Trichomoniasis is a common cause of
vaginitis. In some cases, the infection is
sexually transmitted.
In women, the causative organism
may inhabit the vaginafor years without
causing symptoms. If symptoms occur,
they include painful inflammation of
the vagina and vulva, and a greenish,
frothy, offensive-smelling discharge. Men
usually have no symptoms.
The diagnosis is made from exami-
nation of a sample of the discharge.
Diagnosis usually difficult in men. Treat-
ment is with metronidazole. The sexual
partner or partners of an infected per-
son should be treated at the same time
to prevent reinfection.
trichotillomaniaThe habit of cons-
tantly pulling out one’s hair. It can be
associated with severe mental handicap
or with a psychotic illness. It may also
occur in psychologically disturbed chil-
dren. The sufferer typically pulls, twists,
and breaks off chunks of hair from the
scalp, leaving bald patches; occasionally,
pubic hair is pulled out. Children some-
times eat the removed hair, which may
form a hairball in the stomach, known
medically as a trichobezoar (see bezoar).
Treatment depends on the cause, and
may consist of psychotherapyor anti-
psychotic drugs.
trichuriasisA parasitic infestation with
the tropical worm TRICHURIS TRICHURIA
(whipworm). Children are most com-
monly affected. Infestation occurs when
eggs are ingested and develop into
adult worms in the intestines. Severe
infestation may cause bloody diarrhoea,
abdominal pain, and weight loss. Treat-
ment is with anthelmintic drugs.
triclosanAn antiseptic.
tricuspid incompetenceFailure of the
tricuspid valveto close fully, allowing
blood to leak back into the right atrium
whenthe right ventricle contracts. The

condition, which

is also known as

tricuspid insuffic-

iency, reduces the

pumping effici-

ency of the heart.

The usual cause is

pulmonary hyper-

tension, but more

rarely, it follows

rheumatic fever,

or, in intravenous

drug users, a bac-

terial infection of

the heart.

Tricuspid incom-

petence results in

symptoms of right-

sidedheart failure, notably oedemaof

the ankles and abdomen. The liver is

swollen and tender, and veins in the

neck are distended.

A diagnosis is made from the symp-

toms, from hearing a heart murmur

through a stethoscope, and by tests that

may include an ECG, chest X-rays, echo-

cardiography, and cardiac catheterization.

Treatment with diuretic drugs and ACE

inhibitorsoften relieves the symptoms.

tricuspid stenosisNarrowing of the

opening of the tricuspid valve, usually

caused by a previous attack of rheumatic

fever. Tricuspid stenosis is uncommon

and often occurs with another heart-

valve disorder. For example, tricuspid

incompetencemay also occur in intra-

venous drug users who have a bacterial

infection of the heart. Tricuspid stenosis

causes enlargement of the right atrium.

The symptoms and diagnosis are simi-

lar to those of tricuspid incompetence.

Treatment is with diuretic drugsand

sometimes a digitalis drug. Heart-valve

surgeryis sometimes needed.

tricuspid valveA valve in the heart

consisting of 3 flaps that lies between

the right atrium and the right ventricle.

It ensures that blood flow from the atri-

um to the ventricle is in 1 direction only.

tricyclic antidepressantsA type of

antidepressant drug. Tricyclic antidepres-

sants prevent neurotransmittersin the

brain from being reabsorbed, thereby

increasing their level. Examples are ami-

triptyline, clomipramine, and imipramine.

TRICHOMONIASIS TRICYCLIC ANTIDEPRESSANTS

T

Tricuspid

valve

TRICUSPID VALVE

Aortic

valve

STRUCTURE OF HEART

Right

ventricle