Medical Jurisprudence And Toxicology

546 MEDICAL JURISPRUDENCE

to loosen about the seventh day, and falls off from the fourteenth to the
nineteenth day. Thallium acetate is also used for removing the superfluous
hair, and is a constituent of some proprietary depilatory creams.

Thallium sulphate is used for killing rats. It is a constituent of rat-
poison pastes, known as Zelio-paste and Zelio-grains (corn), which are used
in Germany and other countries.

Thallium is a highly poisonous substance, resembling lead in all its
characters. Taken in a large dose, it acts as an irritant to the stomach and
has a selective action on highly specialized cells of the body, causing marked
fatty degeneration in the heart and liver and necrosis in the kidneys. Taken
in small doses for a prolonged period, thallium has a cumulative effect.

Acute Poisoning.—The symptoms of acute poisoning occur from a few
hours to fourteen days after the administration of a therapeutic dose of
thallium acetate due to personal idiosyncrasy or an overdose through an
error of the dispenser. In mild cases the symptoms are joint pains in the
legs and feet, loss of appetite, drowsiness, and hypochlorhydria. These
generally pass off in a few days.

In severe cases the symptoms are dryness in the mouth, difficulty in
swallowing, colic, vomiting, diarrhoea, pains in the muscles, joints and nerves,
albuminuria, delirium, convulsions, collapse and death. There may be
drowsiness followed by coma. After recovery the patient may suffer from
peripheral neuritis, optic atrophy, loss of sight and hearing, and mental
disorders.

Chronic Poisoning.—This occurs among workmen employed in a chemical
factory where thallium is isolated from pyrites residues. Chronic poisoning
also occurs among the persons who use a depilatory cream containing
thallium acetate for a prolonged period.

The symptoms consist of restlessness, insomnia, fatigue, loss of appetite,
abdominal colic, pains in the lower limbs, tachycardia, epilation, marked
eosinophilia, lymphocytosis, sometimes optic atrophy, loss of knee jerks and
injury to the endocrine glands. Changes similar to those observed in
arsenical poisoning are sometimes noticed in the nails.

The falling out of the hair of the head is the most striking and important
clinical diagnostic symptom of poisoning by thallium.

Fatal Dose.—Uncertain, although the therapeutic dose of thallium acetate
has caused death. Two grammes of thallium sulphate may be regarded as
a fatal dose.

Fatal Period.—The average fatal period is twenty-four to thirty hours,
although death occurred in twenty-four hours after ten times the normal
dose of thallium acetate.17 Death has also occurred from the second to the
sixteenth day after the administration of therapeutic doses.38 Two boys,
each aged 9 years, died in five days from the effects of 5 grammes of thallium
acetate wrongly prescribed for 0.5 gramme.10

Treatment.—Wash out the stom,ach and give large quantities of milk.
Administer intravenously 20 cc. of a 3 per cent solution of sodium thiosulphate
per day. Inject intramuscularly B.A.L. as early as possible to make
it effective. Administer potassium iodide and saline purgatives to aid the
elimination of thallium from the system. Keep the patient warm and admin-
ister hypodermically heart stimulants for shock,

Post-mortem Appearances.—The mucous membrane of the stomach may
be inflamed with submucous petechial haemorrhages. The spleen is congested.

17. Roche Lynch and Scovell, Lancet, Dec. 20, 1930, p. 1340.

18. Brit. Med. Jour., Jan. 6, 1934, t>. 26.

19. Jour. Amcr. Med. Assoc., June 22, 1935, p. 2280.