Uric acid is a substance about which more has been written and less understood than many others in medicine and that is saying a great deal. As a basis of the suboxidation theory of Bence Jones' day, as the cause of gout with Garrod, as a step in our knowledge of metabolism and as a popular fad, uric acid in its time has played many parts.
Uric Acid in Hay Fever. In 1893, Dr. Seth Bishop announced before the American Medical Association that "excess of uric acid in the blood causes hay fever and nervous catarrh;" and advised elimination and control of the uric acid as the principle of treatment. The article may be found in the Journal of the American Medical Association, 1893, and abstracted with an interesting discussion on the treatment of hay fever, in the Philadelphia Medical News, 1894. This position, of course, is also that of Haig (Uric Acid, seventh edition, page 386) and his followers.
Now, in 1893, the theory of uric acid poisoning flourished like a green bay tree and all sorts of queer and misunderstood pathological processes came and roosted in its branches. Patients came to our offices, not complaining of headache or lumbago or cough, but asking for "something for that uric acid." As patients will, they had already made the diagnosis from the newspapers and wished our advice only for the remedy.
As the basis of hay fever, this theory of uric acid poisoning has apparently made as little impression as de Mussy's theory of gout on the nose and throat specialists of this country and Great Britain; for I find no mention of it in their books, except the brief reference of Professor Grayson quoted in the preceding chapter. In the Virginia Medical Monthly, however, I find an interesting paper by Dr. John Dunn, Professor of Diseases of the Nose and Throat in the University Medical College of Richmond, Virginia. Following the suggestions of Dr. Bishop, Dr. Dunn treated his patients with diet and alkalies according to the uric acid theory and reports excellent results.
It may be pointed out that the successful results of the treatment by no means prove that the condition was due to uric acid; for the diet may be doing many other things besides controlling the movements of the uric acid and it is probable that the effect of an alkali in the blood is not a simple neutralizing of an acid but that it sets in motion a train of chemical changes of great complexity. None the less, Dr. Dunn's paper is well worth reading by every physician for its practical suggestions in the treatment of hay fever.
The cardinal error made by the advocates of the uric acid poisoning is that they name the poison. If the theory were stated that an unknown poison or poisons circulate in the blood and cause many symptoms of disease, as headache, gouty pains, bilious vomiting, and so on, we would all agree that this is so. Call it the X-poison, if you will, as Roentgen did with his unknown ray. But when you name the poison uric acid, you challenge the chemist and the physiologist to test your doctrine by chemical analysis, and when the uric acid doctrine is tested in this way it is found sadly wanting.
It is true that uric acid in the form of urates is found in the blood in varying quantities, but there is no proof that it does any harm there. In fact, there is good evidence that it does not. In the disease, leukæmia, there is an enormous amount of uric acid in the blood, far more than was ever demonstrated in gout or the so-called uric-acid disorders; yet, in leukæmia, there are no symptoms of gout or any other symptoms that have been attributed to uric acid poisoning.
A second error of the uric acid advocates, flowing from their first error of naming the poison, is to pour their acids and alkalies into the blood with the childlike faith that, like good children, the acids and alkalies will go in there and do just what they were told to do, neutralize the uric acid, and get out. They assume that the chemistry of the acids and alkalies is as simple inside of the body as it is outside of it and that the blood is simply a passive mixture of chemicals.
A third error of the uricacidites is to talk so glibly of the chemistry of the blood and the influence of this or that food or medicine on its chemical changes. The chemistry of blood! A subject of which the ablest physiological chemists have but touched the fringe,—is that a knot to be unloosed familiar as his garter by an amateur with a watch-glass and a thread?
In his Lehrbuch der Organischen Chemie für Mediciner, Leipzig, 1906, Bunge observes slyly that he had "sometimes had occasion to remark in private that the less a physiologist knew about chemistry, the more irresistible was his impulse to undertake the most difficult subjects."