This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Among the earlier symptoms of lead-poisoning are dryness of the mouth and nostrils, diminished urine, and a tendency to costiveness, with small, dry, and sometimes light-coloured stools, evincing diminished biliary and intestinal secretion. There are often also uneasy epigastric sensations, impaired appetite, colicky pains, and sometimes nausea and vomiting. If the gums are now examined, they will generally present a bluish or slate-coloured line along their margin, of greater or less extent; and the same discoloration will be found to affect the teeth themselves, where joined by the gums. This appearance is ascribed to the formation of sulphuret of lead, probably through the agency of the saliva acting upon the metallic combination in the tissue. It has also been noticed in the mucous membrane of the lips and cheeks. It is said that the habit of cleaning the teeth or gums daily with a brush has some effect in preventing this blue discoloration, the absence of which, therefore, in persons who thus use the tooth-brush is no proof that they may not be labouring under the effects of lead. (Dr. Alexander Smith, Ed. Med. Journ., July, 1856, p. 10.) Except in such cases, the blue line almost always occurs, sooner or later, under the continued use of lead, even when no poisonous symptoms are observed. A sweetish, astringent taste, and a peculiar offensive odour of the breath, are said to accompany the poisonous action of lead, which is also characterized by emaciation, especially of the face, and by a dirty yellowish hue of the conjunctiva and the skin. The circulation is usually somewhat depressed, as evinced by the slow and contracted pulse; and the mind is often dejected. This cachectic condition may exist, for a long time, without any other very striking phenomena; but much more frequently it is attended either with violent abdominal symptoms, constituting a variety of colic, with external nervous disorder in the form of neuralgia or paralysis, or with serious cerebral affections. These different complications may exist in the same or in different persons, and, in the former case, may occur successively, or in a greater or less degree conjointly. The most frequent of them, and usually the first in the order of time, is the affection called variously, colica pictonum, painters' colic, or lead colic, which is ordinarily described as a distinct disease.
Lead colic is characterized by severe pains about the umbilicus, occurring more or less paroxysmally, in general not increased but rather relieved by pressure, with sensations of twisting, and a feeling of wretchedness, often strongly expressed upon the countenance. The walls of the abdomen are usually hard and somewhat retracted, and the muscles not unfrequcntly gathered into knots. The bowels are obstinately constipated, though there may be frequent desire to go to stool, with straining and tenesmus. Bilious vomiting is not uncommon. The patient loses sleep, and is extremely restless, often changing his position, and sometimes rising and walking about the chamber, with his body stooping, and both hands pressed upon the abdomen. If the cause be withdrawn. these symptoms will generally subside in a few days, especially under appropriate treatment; but they sometimes assume a protracted form, and, more or less moderated in violence, may run on for weeks or months.
Lead palsy may occur among the earlier phenomena, but is generally a sequela of the colic. It may affect sensation and the power of motion severally or conjointly, and, when it affects both, may do so in different degrees. It is frequently accompanied with neuralgic pains in the muscles, joints, etc., counterfeiting rheumatism, which are usually continuous, though liable to exacerbations, and are increased by motion, but relieved by pressure. Sometimes there is spasmodic rigidity of certain muscles. The part first attacked with palsy is generally the hand and forearm; and the extensor muscles are chiefly affected, so as to cause the hand, when the arm is held up, to fall as if strongly flexed. The falling hand is among the most striking diagnostic symptoms of lead-poisoning. The lower extremities are also attacked in some cases; and there is, particularly in the advanced stages, a general defect of muscular power, evinced by tremulous movements, and especially by trembling of the tongue when protruded. The involuntary muscles participate in some degree in the palsy, and the power of the heart becomes at length very sensibly diminished. The external paralytic and neuralgic complications are generally more difficult to cure than the colic.
By far the most serious effects of lead are those upon the brain. They usually occur at the close of protracted cases; but sometimes early, either by themselves, or associated with colic or palsy. Among the-most prominent are convulsive attacks similar to those of epilepsy. which are generally fatal. Sometimes the muscles become cataleptic; and sudden comatose seizures imitating apoplexy now and then occur. Impaired sight and hearing, complete amaurosis, diminished general sensibility, delirium, stupor, and coma, are usually the last effects of the poison.
Albuminuria has in several instances been noticed as one of the results of poisoning by lead. It is apt to accompany the cases complicated with cerebral disease and amaurosis, and may serve to account in part for these affections, through the uremic poisoning of the blood.
Lead-poisoning may end fatally in an acute attack, or may last for years, with alternations of exacerbation and remission, of seeming recovery and relapse, or with a more or less continuous course of deterioration of health, under an intermittent or steady exposure to the cause.*
Applied locally, and in a quantity insufficient to irritate, the preparations of lead produce contraction with some diminution of sensibility in the surface, and, if continued, generally occasion a bluish colour, probably by penetrating into the tissue, and forming there some new chemical combination.
Anatomical Changes. The blood is deficient in red corpuscles. In one case examined by Andral, they had been reduced to 83.8 parts in 1000. the mean normal proportion being about 125. The serum has a yellowish hue, as also have the viscera. In some cases, no alteration is observable in the bowels; in others, one portion has been found contracted, and another dilated in the same subject. In cases attended with albuminuria, there is produced in the kidneys, according to M. Lancereaux, a new formation of connective material, which causes the retrogression or absorption of the epithelial cells. (Ann. de Therap., 1864, p. 215.) No characteristic lesion has been noticed in the brain or spinal marrow; but the muscles long affected with paralysis are usually pale and atrophied, and the heart and blood-vessels are said sometimes to be contracted. Lead has been discovered in the tissue of all the organs which have evinced signs of its poisonous influence during life.