I think that, from the evidence examined, we may say that British and American authors know nothing of de Mussy and his theory.
Next, I looked up the gout authorities, Ewart, Ebstein, Garrod, Falkenstein, Lancereaux, Lecorche, each of whom wrote a bulky treatise on Gout, but there is never a word on Hay Fever.
De Mussy in Germany. For many years, whenever I have wanted to know anything from the bottom up, historically, linguistically, philosophically, I have turned to a German book and have always found what I was looking for, if it is known to man. Where an American or British author will skim over or touch a subject carelessly, not seeming to care where the idea comes from or its relation to other ideas in different times or countries, a German will plow steadily through the matter from Hammurabi to Wilhelm III and lay bare all the collateral tributaries and branches, always with an index at the end.
First I tried Heymann's Handbuch der Laryngologie und Rhinologie (Wien, 1900) and found hay fever described in the article on Die Nasalen Reflexneurosen, by Professor Jurasz in Heidelberg; but there was no mention of gout. By this, I was truly convinced that nothing was known on the subject. If a Heidelberg Herr Professor does not know it, it does not exist. And "Professor Jurasz in Heidelberg" had failed me.
However, looking further in Heymann, my faith in German thoroughness and all-inclusiveness revived. Hay fever appears also in the article on Acute Rhinitis, by P. H. Gerber, of Königsberg, and here, on page 371, we find a complete "Literatur" spread out in true Teutonic style from Bostock to date. However, Gerber does not discuss the matter of gout in the text, but says merely, "Recently Bishop asserts that the nervous disturbances of hay fever are due to an excess of uric acid in the blood."
The gouty theory of hay fever receives scanty recognition from most German writers. Strümpell does not mention it. In his Handbuch der Specielle Pathologie und Therapie, Berlin and Wien, 1904, Eichorst says skeptically, page 326, "It has been stated often that gouty families are especially apt to develop hay fever," and on page 330 "Grote saw hay fever patients of gouty families cured (?) by a course of waters at Neuenahr."
In Eulenberg's Real-Encyclopædie der gesammten Heilkunde, 1887, page 509, article Hay Fever, we read:
"Of general diseases, malaria and gout have been advanced as the basis of hay fever, but without convincing proof."
We may conclude, then, that while British and American physicians know nothing about the gout theory, German physicians know about it but do not believe it.
Finally, in my wanderings through German encyclopædias, I came to the many-volumed Nothnagel and here, at last, found a modern writer who knew de Mussy and recognized the importance of his observations. At the end of Volume 4 there is a monograph on Hay Fever by Dr. George Sticker, of the University of Giessen, the most thorough and satisfactory book on the subject that I have found. It may be read in English in the American edition of Nothnagel, Philadelphia, 1902. Sticker resists the impulse to begin with Galen, though he notes rather wistfully that John Mackenzie of Baltimore succumbs to it. He gives the most complete statement in any modern book of the gout theory of hay fever, but, alas, Sticker misses the pearl in the oyster. He says nothing of de Mussy's recognition of the urticarial nature of the lesion in hay fever.