Lead poisoning and lead absorption

by Sir Thomas Morison Legge; Kenneth Weldon Goadby

Lead Colic.

—Probably the commonest symptom, and the one for which first and foremost relief is sought, is abdominal colic. The colic of lead poisoning, when once seen, is rarely mistaken a second time. The pain is generally referred to the lower portion of the abdomen, low down, and often the sufferer points to a position immediately above the pubes; pain may often be referred also to the right iliac fossa, and on this account the possibility of appendicitis, or even perityphlitis or chronic colitis, must not be forgotten.

Colic, as shown in the statistics on [p. 49], is the chief symptom complained of. No doubt, as has been previously suggested, the fact that colic is so common a symptom induced earlier pathologists to regard the entrance of lead through the gastro-intestinal canal as being the portal of lead infection. We have, however, demonstrated in the chapter on Pathology that the absorption of lead, particularly in industrial processes, is mainly by way of the lung, and in the résumé of the literature it has already been pointed out that strong evidence exists for regarding colic and other abdominal symptoms associated with pain as due to vaso-motor disturbances in the splanchnic and mesenteric areas.

Lead colic is usually irregular, with marked exacerbations and remissions, and in the acute form the legs are drawn upwards towards the abdomen, the body is flexed at the hips, the face anxious and drawn, whilst the body is covered with a cold sweat, the eyes are staring, and convulsive movements of the limbs occur. The sufferer often finds relief from firm pressure upon the abdomen, a point of considerable importance in diagnosis; the pain is not increased, but distinctly relieved, by firm pressure.

If the abdomen be digitally examined during a paroxysm of pain, the intestines will be found contracted under the fingers, often in an irregular fashion. In an animal acutely poisoned with lead the intestines are found irregularly contracted during a very large portion of their length, and when removed from the body have the appearance of a string of sausages. There is evidence that spasmodic contraction of the circular fibres of the muscles of the mucosa has taken place, and the wave of peristalsis, moving forward, meets with a block at these points of constriction, thereby causing pain.

The colic affecting the lower part of the abdomen may possibly be related to the excretion of lead into the large intestine, and the affection of the bloodvessels in the mesentery, and in animals poisoned by means of lead the vessels in the mesentery, particularly in the region of the ileo-cæcal valve and the large intestine, are engorged with blood.

During a paroxysm the patient frequently screams in agony and rolls about upon the bed or the floor. Temporary relief may be obtained by leaning upon a pillow placed upon the back of a chair. The relief afforded by such procedure is also strongly in favour of the vaso-motor origin of the pain. During the spasm the abdomen is retracted, and fibrillary twitching of the abdominal parietes may often be seen; a constant desire to go to stool is generally present, but only results in straining and, perhaps, the passage of a little mucus and blood.

Vomiting is often associated with this stage, and the patient frequently vomits a considerable amount of thick, tenacious mucus. The vomit is not uncommonly regarded by the patient as composed of white lead, if he has been working in that industry. Tanquerel in 1,217 cases noted vomiting 400 times, and marked retraction of the abdomen 649 times. Occasionally the patient complains of a sense of great weight in the abdomen, particularly in the intervals between the spasms of pain.

During the exacerbations of colic very marked diminution in the pulse-rate takes place, a fact that has already been referred to in the section dealing with vaso-motor disturbances. The pulse may be as low as 20 beats per minute, but it varies generally between 40 and 50 per minute.

Very occasionally the first stage of colic is associated with a slight rise of temperature. This must be regarded as an intercurrent affection rather than as one definitely associated with lead poisoning. Probably in such circumstances a gastritis other than the lead vaso-motor colic is the reason for the elevation of temperature, but it may confuse the diagnosis, suggesting rather an acute gastritis than lead colic. Under normal conditions the temperature falls during the colic, the extremities are cold, and the body is covered with a moist perspiration, the temperature dropping to 96°, and even lower.