TREATMENT
In laying down the general lines of treatment for both lead poisoning
and lead absorption, it is essential in the first place to distinguish
carefully between the two states; for although lead absorption may
gradually drift into definite lead intoxication and lead poisoning,
with all the classical symptoms associated with the saturnine cachexia,
a large number of cases, particularly those in industrial processes,
do not and should not progress beyond the early symptoms of lead
absorption. The treatment, therefore, will depend in the first place on
whether the case be one so constantly met with in industrial processes,
where generalized symptoms of lead absorption are manifest without any
definite and disabling symptoms traceable and sufficiently pronounced
to enable a diagnosis of lead poisoning to be made.
The facts given in the chapter on Pathology, on the methods of entrance
of lead, on the toxic manifestations, and the blood-changes, and, above
all, the facts relating to microscopical hæmorrhages and other profound
changes in the bloodvessels, point clearly to the lines along which the
general treatment for amelioration, prevention, or cure of poisoning
should be undertaken.
The treatment of the so-called “presaturnine state,” or what is
preferably termed the “state of lead absorption,” is one that the
appointed surgeon or certifying surgeon in lead factories or other
processes in which lead is manufactured or used, is constantly called
upon to treat. Lead poisoning is a definite entity as a disabling
disease, whereas lead absorption, although the prodromal stage of
such disease, cannot be defined as actual lead poisoning, as in many
instances persons may show signs of continued lead absorption, but
their powers of elimination can be maintained at such a level that the
ratio of absorption to elimination remains in equilibrium.
With the preventive treatment of lead poisoning we have dealt in
another place (see p. 199). What is particularly required here is the
medicinal treatment, which may be helpful in preventing lead absorption
passing on to definite lead poisoning.
For many years it has been customary in the treatment of men employed
in lead works to give occasional purgatives, and it is, moreover, a
common and proper precaution to keep a stock of some simple aperient
medicine, preferably saline composed of sodium sulphate and magnesium
sulphate, at the works in charge of the foreman, so that any man who
so desires may obtain a dose of an ordinary aperient mixture. We
have seen from the pathological evidence that the largest proportion
of lead is excreted by the bowel, and that, therefore, the sweeping
away of the bowel contents--particularly where constipation is set
up--will naturally tend to remove from the body a good deal of the
lead which has been already excreted into the intestine and which
may presumably become reabsorbed unless it be swept away. In a large
electric accumulator factory Epsom salts in the form of the granular
effervescing preparation is much appreciated. In winter 50 per cent.,
and in summer 90 per cent. of the men are said to take a daily
dose. In an important white-lead works chocolate tablets containing
hypo-(thio-)sulphite of sodium are supplied to the workers.
Another medicine made use of in lead works is the sulphuric acid
lemonade, this being acidulated with sulphuric acid and flavoured
with lemon. It is very questionable whether this substance has any
definite effect in the special direction in which it is supposed to
work--namely, that of forming an insoluble sulphate of lead in the
stomach and so preventing its absorption. The use of this drug was
suggested on the presumption that lead poisoning as a rule took its
origin from the dust swallowed and converted into a soluble form in
the stomach. As we have seen, there is very little evidence that this
entrance of lead is of much importance, although it does occasionally
take place. Furthermore, from the experiments of one of us [K. W.
G.[1]], it has been found that the sulphate of lead is at any rate as
soluble as other lead salts, such as white lead or litharge, when acted
upon by normal gastric juice.
With regard to the drinks supplied to workers in lead factories, it
is highly important that some form of fluid should be supplied which
the men may drink without harm, particularly in the more laborious
forms of employment, and, above all, in the factories where smelting,
desilverizing, etc., of lead is carried on. In these factories
the use of some type of lemonade containing sodium citrate is to
be recommended, as it has been shown that one of the pathological
effects of lead absorption is to produce an increased viscosity of
the blood, and the use of such drugs tends to some extent to diminish
this. A drink containing a few grains of sodium citrate to the ounce
and flavoured with lemon is freely drunk by workmen engaged in the
laborious processes.
Finally, as a general routine treatment, it is advisable to keep at
the factory some form of mixture containing iron, which may be given
to those persons who are showing signs of slight anæmia, generally
associated with some degree of constipation, and it is therefore better
to use a form of iron cathartic. This medicine should also be kept in
the care of the foreman, who will see that it is administered to the
men properly. In this way any persons who at the weekly examination
exhibit signs of anæmia may be promptly treated, and what is more, the
surgeon is assured that the workmen in question actually obtain the
medicine prescribed regularly.
During the routine weekly or monthly examination, or at whatever
intervals the medical examination takes place, particular attention
should be paid to the records kept of the state of health of the
various persons, and whenever possible alteration of employment should
always be enjoined when early signs of anæmia make their appearance.
The surgeon should spare no pains to determine if any of the workmen
are confirmed alcoholics, and such persons should be removed from
work in dangerous processes, while at the same time care should also
be taken to eliminate any persons suffering from those diseases which
are known to be predisposing causes of lead poisoning. The card system
of registration of any symptoms noted or treatment given facilitates
supervision of the health of the men.
In times of stress where some particularly dangerous process is in
operation, as, for instance, where portions of a building which
has become thoroughly impregnated with lead dust is being pulled
down, or where machines are being altered, removed, or rebuilt,
especial care should be exercised with the workmen so employed, and
it is advisable in such cases to adopt preventive measures on the
supposition--generally correct--that such persons are absorbing a
larger quantity of lead owing to their peculiarly dusty employment than
they were under normal circumstances. At such times, also, it may be
advisable to administer some form of mild iron cathartic to all persons
employed in the factory for, say, a week at a time. It must not be
supposed, however, that these methods of treatment in any way supersede
the precautions for the prevention of lead poisoning by mechanical and
hygienic means; they are merely additional precautions which may be put
in force under special circumstances.
=The Treatment of Lead Poisoning.=--The treatment of definite lead
poisoning, as the treatment of lead absorption, is directed towards
the elimination of the poison, the promotion of repair to the damaged
tissues, and special treatment directed towards those special organs
which suffer mostly in lead poisoning. At the same time, special
treatment of urgent symptoms may be called for; but in the treatment of
the urgent symptoms the fact of the general elimination of the poison
must not be lost sight of.
We have already seen that the channel through which the poison leaves
the body is mainly the fæces. Treatment must therefore be directed,
as in the former instance (lead absorption), towards eliminating the
poison by this means as much as possible, both by the use of enemata,
and later the use of sulphate of magnesia, which may be added to the
ordinary fluid enema; and it is far better in obstinate cases of
constipation and colic to give enemata than to continue with the huge
doses of salines or other aperients, such as croton-oil, elaterinum, or
castor-oil.
=Colic.=--Lead colic may be simple, acute, recurrent, or chronic and
continued. In whatever form colic appears pain is invariably referred
to the lower part of the abdomen, frequently into the groins, and
occasionally to the umbilicus. The pain has to be distinguished
particularly from acute gastritis, and occasionally from appendicitis,
and sometimes from that of typhoid fever. Acute colitis--not common in
this country--and dysentery, may, to some extent, simulate the pain of
lead colic, but John Hunter’s[2] original definition of “dry bellyache”
conveys very vividly the type of pain. Occasionally diarrhœa may be met
with, but as a rule obstinate constipation is present. In continued
colic, or chronic colic, sometimes lasting for several months,
obstinate constipation is the rule. In the simple acute colic the pain
passes off in the course of five or six days, generally disappearing
about four days after the lower intestine has been thoroughly cleared.
The pain of lead colic is relieved by pressure upon the abdomen,
whereas that of gastritis and most other forms of abdominal pain
may be generally elicited along the descending colon and splenic
flexure; mucus is commonly found in the stools, especially the first
evacuation, after obstinate constipation occasionally of several
days’ duration associated with an ordinary attack of lead colic.
Blood may be passed, but this symptom is not common. The pain in the
acute form is paroxysmal; it is rarely persistent, being typically
intermittent. During the paroxysm distinct slowing of the pulse-rate
with an increased blood-pressure takes place, and the administration of
vaso-dilators--such, for instance, as amyl nitrite--during a paroxysm
rapidly relieves the pain and lowers the blood-pressure, and in this
way distinguishes acute colic of lead poisoning from, say, subacute
appendicitis.
Vomiting may or may not be present, though the patient usually
complains of feeling sick, but there may be at times vomiting of a
frothy mucus.
It is unusual for a patient to die from acute colic, but acute
paroxysms have been recorded in which yielding of the blood-vessels of
the brain has occurred.
Recurrent colic is as a rule less severe than the simple acute form,
but may last for several weeks, clearing up for three or four days at
a time and then recurring with little diminution in violence from the
first attack. Such cases are probably due to the gradual excretion of
lead by the intestine, and should be treated on this supposition.
In the continued or chronic colic the pain may persist for as long as
two months, during the whole of which time the patient complains of
uneasiness and even constant pain in the lower part of the abdomen,
which becomes considerably worse after each evacuation, and almost
invariably is associated with exceedingly obstinate constipation. It is
this type of case that olive-oil or liquid paraffin relieves, while in
the acuter forms drastic purgatives such as castor-oil, croton-oil, or
pulv. jalapæ comp. may be administered.
For the treatment of pain in colic one of the various vaso-dilators
should be used, as, in addition to the spasm of the intestine, a very
considerable vaso-constriction of the whole of the vessels in the
mesenteric area occurs. Amyl nitrite gives immediate relief, but the
effect passes off somewhat rapidly, whilst scopolamine, although taking
somewhat longer to act, is better for continuous use, as its action is
longer maintained. Sodium nitrite, liquor trinitrini, and antipyrin are
also of use. Atropin may be used, but it is perhaps better given in
conjunction with magnesium sulphate.
Whatever form of purgative is given, some form of anodyne should be
combined. Drissole and Tanquerel[3] are said to have obtained excellent
results with croton-oil; one drop is given, followed seven or eight
hours later by another, and then by an enema of 2 pints of normal
saline. After two or three days the croton-oil may be again given, one
drop at a time each day. In addition, Tanquerel made use of belladonna
and opium together, finding that their combined action was better than
that of opium alone, as the physiological effect of belladonna probably
assists in preventing the intestinal cramp.
Hoffmann[4] recommends the use of olive-oil and opium, giving 3 to
4 ounces of olive-oil. He says that this relieves the spasm of the
pylorus, and is of particular use where severe vomiting is associated
with the colic. This use of olive-oil, first suggested by Hoffmann
in 1760, and revived by Weill and Duplant[5] in 1902, is somewhat
interesting, in view of the modern tendency to administer paraffinum
liquidum in the treatment of chronic constipation.
Briquet[6] recommends 4 grammes of alum and 4 grammes of dilute
sulphuric acid three times daily, with the addition of 0·05 gramme of
pulv. opii at night. Briquet says that although the purgative method
rapidly diminishes the colic, the elimination of the poison does not
take place as rapidly as by means of the treatment he recommends,
though it is open to doubt whether the use of either of these two
drugs is likely to produce any further neutralization or excretion of
absorbed lead than sulphate of magnesia. It is quite certain that the
magnesium sulphate does not act as a neutralizer of the poison, as in a
factory where sulphate of lead is manufactured some cases of definite
lead poisoning occurred, in which at least half must have been due to
the inhalation of lead sulphate dust. Under these circumstances it
seems hardly worth while to attempt to form a sulphate of lead in the
body. The action of magnesium sulphate and other salines, however,
in promoting the flow of fluid towards the intestines, and rapidly
diluting and washing out the contents, tend to eliminate such lead as
has already been excreted into the bowel.
A number of other drugs have been given from time to time for the
purpose of forming an insoluble compound with the metal in the
intestine, such, for instance, as sulphur in many forms, which is still
much used in French hospitals. Peyrow[7] advises sulphide of soda,
whilst Meillère prefers potassium sulphide as being less irritating.
He considers sulphuretted hydrogen a proper prophylactic against
reabsorption. Both experimental work and clinical observation show
that a change to sulphide does take place in the lower bowel, and that
staining of this part of the intestine is due to lead sulphide; but
as the figure on Plate II. shows, the lead may exist in the form of
granules of a dark nature, deeply embedded in the intestinal wall,
besides being situated in the exterior.
Stevens[8] suggests the use of ¹⁄₂-grain doses of calcium permanganate
thrice daily to relieve pain.
A certain number of other drugs may be also made use of from the point
of view of diminishing the pain, and one French observer advocates the
hypodermic injection of cocaine, but it is doubtful whether any good
would follow from such a procedure. Hypodermic injections of morphia
should be given whenever the pain is great, and diaphoretics as well
as diuretics should also be given, such, for instance, as ammonium
acetate, citrate of potash, or soda. Chloroform water and chloral and
bromine water may be also used, and when no other drug is at hand, the
inhalation of chloroform will rapidly relieve the acute vaso-motor
spasms associated with colic.
During the attack of colic, and for at least a day subsequent to its
disappearance, the patient should be kept on a fluid diet; milk is
best, and 10 grains of sodium citrate should be added to each glass of
milk. After the colic has subsided, a light farinaceous diet should
be given, and it is better not to give meat until at least a week has
elapsed. Alcohol is to be avoided.
=The Anæmia of Lead Poisoning.=--As has been pointed out in Chapter
VIII (p. 135), the anæmia of lead poisoning is one due to the
destruction of the red blood-cells. This is evidenced not only
by the curious sallow complexion, by the occasional presence of
hæmatoporphyrin in the fæces and urine, and often by the curious
yellow of the sclerotics, but also by an increase in the viscosity of
the blood itself. Moreover, the urine of persons suffering from lead
poisoning is invariably highly coloured, and may even show the presence
of methæmoglobin. As the anæmia is generally a symptom of continued
lead absorption for a long period, and does not necessarily occur with
every case of colic--in fact, acute colic may often supervene without
any symptoms of continued anæmia--the persons suffering from lead
anæmia should be removed from their direct contact with the dangerous
processes, and should be given, if possible, work in the open air.
Iron and arsenic may be used, preferably in combination, whilst the
iodide of iron often gives good results. Whatever preparation of iron
is given, care should always be exercised in avoiding any constipating
effect, and the free action of the bowel should be maintained, together
with a liberal supply of milk. Potassium iodide may be also given.
With regard to the action of potassium iodide, there is division of
opinion amongst various physicians as to the efficacy of the drug in
the elimination of lead from the body. At the same time a very large
number of persons hold that the administration of fairly large doses of
potassium iodide in the case of a person suffering from chronic lead
absorption may at times be associated with sudden exacerbation of the
disease, and that the drug apparently may determine the production of
acute symptoms, such as encephalopathy or paralysis, when these have
not been previous features of the case. Our experience supports this
statement, and on more than one occasion one of us (K. W. G.) has seen
a distinct increase of symptoms follow the administration of large
doses of potassium iodide. From a comparison with other cases it seems
that these symptoms would have been unlikely to make their appearance
without some secondary cause. Against this point of view must be quoted
further experiments already referred to by Zinn[9], who found that
when lead iodide was administered to experimental animals iodine alone
was found in the urine; but it must be pointed out that no estimations
were made of the fæces, and it is possible that a certain amount of
lead was eliminated in this way. What exactly is the action of iodide
on the solubility of lead in the body it is difficult to say; yet the
use of iodine compounds has been followed with considerable success
in a number of chronic inflammatory diseases, and it is possible that
it may have the action of splitting off the particular lead compound
from its organic association with the tissues, especially as it is
well known that iodine plays a very important rôle in the process
of cell metabolism. Another point which tends to support the use of
iodine is the fact that the other two halogens, bromide and chloride,
both of which enter largely into cell metabolism, also have a slightly
beneficial effect on the excretion of lead. The dose of the iodine
given should not be large to commence with, 3 grains three times a day
is sufficient, the dose being run up to some 30 or 40 grains per diem,
the symptoms meanwhile being carefully watched.
Other symptoms often associated with the anæmia of lead poisoning are--
_Rheumatic Pains._--These pains are suggestive of muscular affection,
and are possibly due to minute hæmorrhages occurring in the muscle
tissue, which have been discovered in the muscles of experimentally
poisoned animals. For the rheumatic pains diaphoretics and citrates of
soda and potassium may be given.
_Lumbago._--The lumbago constantly complained of in chronic lead
poisoning and even in the early stage of lead absorption, is very
generally related to chronic constipation rather than to a definite
affection of the lumbo-sacral joints.
_Nephritis._--Affections of the kidney associated with lead poisoning
are almost entirely confined to sclerosis. The presence of albumin
in the urine is not a very common symptom. As has been pointed out
already, the presence of lead in the urine is by no means a regular
feature of lead poisoning, though it may at times be present, and the
urine should always be examined for changes in the kidneys; but as a
number of cases of chronic lead poisoning are associated with alcohol
poisoning, the changes in the kidney cell are almost certain to be
present. On p. 95 the illustration showing the disease in the kidney
produced by experimental dosage with lead, and the kidney of a fatal
case of lead poisoning in a man who at the same time had a strong
alcoholic history, shows fairly definitely the difference between these
two points.
Acute nephritis occurs so rarely in the course of industrial lead
poisoning that it cannot be considered to be a disease due to lead.
In chronic nephritis treatment should be along the ordinary lines and
the same remark applies to enlargement of the liver.
_Heart._--Symptoms due directly to disease of the heart are rarely
caused by lead alone. The heart muscle may suffer in the same way
as the other muscles of the body, and in lead poisoning in animals
distinct hæmorrhages are found between the muscular fibres in the heart
muscle, and it is therefore probable that a form of myocarditis may
exist in lead poisoning. This, together with the increased arterial
tension, may cause dilatation, but the symptoms are those related
more to the general condition of arterio-sclerosis than to any direct
heart lesion, and as a rule these symptoms do not call for any special
treatment.
=Treatment of Nervous Manifestations in Lead Poisoning.=--With one
or two exceptions, the diseases of the nervous system associated
with lead intoxication only appear when actual lead poisoning is
established. Certain evidences of affection of the nervous system
are occasionally seen in the prodromal stage, or stage of lead
absorption. These may be merely temporary and disappear often under
treatment, by change of employment and reduction in the quantity of
lead absorbed. Thus, dilatation of the pupils--the reaction to light
being extremely sluggish or absent--is often a feature of the later
stages of the condition of lead absorption. Tremor may also be a
symptom, the outstretched hands exhibiting a fine undulatory movement,
often increased on attempting to perform some act such as touching the
nose, or touching the two fingers together, and when these symptoms
occur they must always be regarded as of somewhat grave import. But it
must be remembered that tremor may occur as a common complication of
alcoholic cases, and further, follows excessively hard manual work,
though there is usually little difficulty in distinguishing between the
various forms.
The symptomology of nervous diseases associated with lead poisoning has
already been carefully set out in Chapter IX., and the pathological
changes underlying these symptoms in Chapter V.
Of the general treatment, little needs to be added to what has
already been stated for the treatment of lead anæmia and general lead
intoxication. Iron and arsenic (not strychnine, especially in presence
of colic), and other similar drugs, should be employed together with
iodides either as potassium iodide or as an injection in the form of an
organic compound, of which there are several varieties on the market.
The injection of normal serum has been advised, as well as saline
injections, and in some instances venesection has been practised,
but it is doubtful whether anything is to be gained by this form of
treatment.
Further, it has been stated that some lead is excreted through the
skin, and for this reason sulphur baths, bathing in sulphuretted
hydrogen water, etc., have been recommended to neutralize any lead that
has gained access to the skin. Serafini[10] has claimed that by means
of electrolytic baths a certain amount of lead can be found present
in the water after continuous passing of a current, and it has been
supposed by these observers that the lead has been actually driven out
of the body under the action of the electric current. It is, of course,
possible that such lead as is discoverable in the water was merely that
which had already become incorporated with the patient’s skin through
mechanical contact.
Whatever form of treatment be adopted of a general type, the patient
must certainly be removed from the chance of any further lead
absorption; a person who is suffering from wrist-drop or other form of
paresis should not be employed in any portion of a lead works where he
may come into contact with any form of lead or its compounds for at
least a year after the paresis has disappeared, and even then it is
inadvisable for such a person to return to any form of dangerous lead
work.
The electrical treatment of the injured nerves and muscles should be
undertaken energetically; both the galvanic or faradic currents may
be used. Probably the best form is the galvanic. A small medicinal
battery may be utilized, the method of application being as follows:
One pole of the battery should be placed over the affected muscle, and
the other pole placed in a basin of water into which the patient’s hand
is dipped. The current should then be passed. It is better not to use
a current of too great intensity, particularly at the start, although
it is found in practice that a much greater current can be borne in
the early stages of the treatment than when the muscles and nerves
commence to recover. As a rule the patient experiences no inconvenience
whatever from a considerable current during the first week of his
affection, but at the end of a fortnight or three weeks less than
one-third of the initial current can be borne. The current should not
be passed continuously, but should be used for a short time and then
shut off, being again switched on for five or six minutes, and then
again shut off. The applications may also be modified by placing one
hand in the vessel of water and stroking the affected muscle and nerve
with the free electrode. The application of the current should be for
not more than half an hour at a time, and may be applied twice in the
twenty-four hours. It is quite easy to instruct the patient to perform
the electrical treatment for himself in this manner when the paresis is
affecting either the upper or lower extremity.
With the faradic current the circuit should be closed while the current
is at a minimum, and then the quantity of current raised to some 15 to
20 milliampères.
For affections of the lower extremity the application may be made by
means of one of the usual baths in which the foot is immersed, the
other electrode being placed on the back or other suitable position.
If both the lower extremities are involved, then both feet should
be placed in a bath into each of which the source of electricity is
connected.
Ionization by means of the faradic current may also be made use of.
For this purpose one of the halogens, preferably iodine or chlorine,
should be used, it being remembered that chlorine and iodine ions enter
from the negative pole, so that in such a case the bath in which the
affected limb is placed must be connected with the negative pole of the
battery.
Subsequently, with either form of electrical treatment, the part
should be well rubbed, and passive movements as well as massage are an
advantage in promoting the return of normal function. As the muscles
gradually return towards their normal state, graduated muscular
exercises should be used.
When treated in the first week or two of the onset, lead paresis
frequently recovers, and in a person suffering from lead palsy for the
first time, confined only to the hands or to a group of muscles in the
shoulder, prognosis is good. The prognosis of palsy of the lower limbs
is not so good.
Paralysis of the facial nerve is occasionally seen in lead poisoning,
and where this occurs it should be treated as previously recommended,
by means of iodides in association with localized electrical treatment.
One pole of the battery should be placed below the external auditory
meatus, and the other one passed over the face on the affected side.
In long-standing cases where no attempt has been made at treatment
in the early stages of the disease, and where considerable muscle
degeneration has already taken place, the prognosis as a rule is
very bad. Efforts should always be made in an early case by passive
movements and massage of the affected muscles to improve their
nutrition as far as possible. The diet should be light, and alcohol
should not be given at any time.
=Affections of the Central Nervous System.=--The typical form of
affection of the central cerebral nervous system caused by lead, is
lead encephalopathy. The disease may be insidious in its onset, and may
be preceded by a long stage of chronic headache with slight or total
remissions. Headaches may last for several months before the actual
acute stage of the disease is reached. In the examination of several
brains of persons who have died from lead encephalitis, microscopic
sections of the brain have shown signs of hæmorrhages which must have
taken place some considerable time prior to death, and were no doubt
associated with the headache that had been complained of for some
time previously, before the onset of the fatal illness. (See Plate
III.) Persistent headache occurring in a lead-worker should always be
regarded with grave suspicion, and such a case should be treated on the
assumption that it is an early case of lead encephalitis. Bromides and
iodides should be given, and the patient placed in quiet surroundings,
and fed on light, nutritious diet, and every attempt made to produce
elimination of the poison.
In the acute attacks vaso-motor spasm is no doubt partially accountable
for the symptoms, and various dilators, previously noted in discussing
colic, may be made use of, such, for instance, as amyl nitrite,
scopolamine, etc., whilst pyramidon, antipyrin, phenacetin, and other
similar drugs may be given between the attacks. Under no circumstances
should any person who has suffered from encephalitis or other cerebral
symptom of lead poisoning be allowed to resume work in a lead industry.
The treatment of eye affections in lead poisoning requires little
comment, as the essential treatment must be the same as in other cases,
mainly devoted towards the elimination of the poison. Attempts may be
made to treat paresis of the ocular muscles by means of mild electric
currents, but of this we have had no experience. About 50 per cent. of
cases of lead amaurosis and amblyopia recover, but a number progress to
total and permanent blindness, and prognosis in such cases must always
be guarded.
=Prognosis.=--The prognosis of the first attacks of lead poisoning of
simple colic or even slight unilateral paresis is good; practically all
cases recover under proper treatment. It is unusual for a person to
succumb to a first attack of simple colic, or paresis.
In most cases the serious forms of poisoning only make their appearance
after three or four previous attacks of colic, but a single attack of
paresis is much more frequently followed by a severe form of poisoning,
such as encephalitis.
A limited number of persons are highly susceptible to lead poisoning,
and these persons rapidly show their susceptibility when working in
a dangerous lead process. Lead poisoning occurring in an alcoholic
subject is more likely to result in paretic and mental symptoms than
in a person who is not addicted to alcohol, and the prognosis of lead
poisoning in an alcoholic is much less favourable than in the case of a
normal person.
Mental symptoms very rarely follow from a single attack of lead colic,
and as a rule do not become established under three or four attacks at
least.
A small number of persons exposed to excessive doses of lead absorption
through the lungs develop mental symptoms, such as acute encephalitis,
without any prodromal stage. The prognosis in such cases is always
exceedingly grave.
Sudden generalized forms of paralysis are not common in the early
stages, but are invariably of grave import. A few cases of paresis,
particularly those of the peroneal type, and affecting the lower limbs,
become progressive, and eventually develop into a condition resembling
progressive muscular atrophy with spinal cord degeneration.
The prognosis of simple colic in women is about as good as for males,
but if an attack of abortion is associated with lead poisoning,
eclampsia often supervenes and permanent mental derangement may follow.
In the dementia associated with lead poisoning the prognosis is not
so grave as in other forms of dementia, especially alcoholic, but
depression is an unfavourable symptom. The mania of lead poisoning is
not so noisy as that of alcoholic mania, but where there is suspicion
of alcoholic as well as lead poisoning the prognosis is exceedingly
grave.
As a rule the prognosis of cases of lead poisoning occurring in
industrial conditions is more favourable when colic is a marked feature
than when it is absent, and there is no doubt that the prognosis
in cases of industrial lead poisoning at the present time is more
favourable than it was before the introduction of exhaust ventilation
and general medical supervision--a fact no doubt to be explained by the
relative decrease in the amount of lead absorbed.
REFERENCES.
[1] GOADBY, K. W.: Journ. of Hygiene, vol. ix., 1909.
[2] HUNTER, JOHN: Observations of Diseases of the Army in Jamaica.
London, 1788.
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