The fundamental error in all the literature on hay fever is the teaching that the lesion is a peculiar kind of catarrhal inflammation; whereas it is not an inflammation at all, catarrhal or any other kind. The symptoms of hay fever resemble those of catarrhal inflammation, but the resemblance is only superficial. The resemblance is striking and must be so to have deceived so many skilled observers, but it is only superficial, nevertheless.
When you see a patient with eyes red and swollen, overflowing with tears and mucus, burning and sensitive to light, you say at once, catarrhal conjunctivitis. In the nose the sneezing, the discharge, the obstructive swelling suggest at once catarrhal rhinitis. But stop a moment. Did you ever cure a catarrhal conjunctivitis or rhinitis in three minutes by moving the patient from one room to another? You can do that with hay fever. If you can remove the patient from the irritating atmosphere, the swelling and redness will subside rapidly, the discharge cease, and in five or ten minutes you would scarcely know by examining the patient that there was anything the matter with his eyes and nose. By returning him to the irritating atmosphere the symptoms will return instantly. By removing him again, they will rapidly subside. I have watched this many times in my own eyes. It was in watching the changes in my own eyes and nose that I realized that this was no catarrhal inflammation but a much more superficial lesion.
Did you ever see a catarrhal conjunctivitis that acted in this way or a cold in the head in which the patient could be cured and catch a fresh cold twenty times a day? I think you never did. A true inflammation requires time, a few hours, for its development, and when an inflammatory exudate oozes into the meshes of the tissue, it requires some days or at least some hours to be absorbed. This one point of rapid appearance and rapid disappearance would forbid our calling the lesion of hay fever a catarrhal inflammation.
Next, associate this rapid appearance and disappearance with the chief symptom of hay fever, the itching, the intolerable itching, of the eyes, nose, and throat, itching that ceases at once on removal from the irritating atmosphere and returns instantly when the irritating atmosphere is reapplied. Turn to the skin, the external mucous membrane. What is that disorder of the skin that appears abruptly, presents redness, swelling, and intense itching, and ceases abruptly after a few minutes or a few hours according to your ability to get rid of the irritating cause,—that can be reproduced any number of times by exposure to the same cause? Why, hives, of course, urticaria or angioneurotic œdema. And a hive (or urticaria or angioneurotic œdema) is not an inflammation. It is a vascular spasm, a spasm of the minute vessels that drain small areas of skin, causing a local stoppage of the circulation in that small area, a turgescence or exudate, the hive. Just as suddenly as it began, the spasm of the vessels may relax, the swollen area is drained rapidly, and the hive disappears, leaving a faint redness. This is exactly the case with hay fever. It is an urticaria, a vascular spasm. The sudden onset in response to a specific irritant and the sudden disappearance—this is no catarrhal inflammation and no rhinitis or inflammation of any kind.
Those cases of hives that appear quickly after chilling the skin are perfect analogues of hay fever, appearing in response to the local irritation of odors and dust. There are cases of hay fever that resemble ordinary hives in being aggravated by certain foods, especially strawberries, acid foods, and malt liquors. This has a practical bearing on treatment; for, in such cases, simply excluding these foods from the diet and the administration of an alkali gives relief. Again, many hay fever subjects suffer from urticaria, as in the case reported to me by Dr. Rice of Hawaii, in which the attacks of hay fever alternated with urticaria.
Sir Morell Mackenzie was wrong when he said that hay fever "had no pathology because it leaves no permanent structural lesion behind it." Hay fever "has a pathology" if urticaria has a pathology, for urticaria, too, subsides and leaves no traces. However, in this statement, we recognize the effort to state the difference between the evanescent lesions of hay fever and the more persistent lesions of catarrhal inflammation; which is just the difference between an urticaria that comes and goes in half an hour and an eczema (catarrhal dermatitis) that takes several days to develop and is attended by a real inflammatory exudate that requires many days for its absorption.
In our text-books, our ablest specialists perpetuate this error by devising such names as hyperæsthetic catarrh, hyperæsthetic rhinitis, vaso-motor rhinitis—and then describing a neurosis. The two ideas will not mix. The very authors who introduce these names feel that there is something wrong with them, for usually they take several pages to explain what the name means. It is better to throw overboard both the name and the idea of catarrhal inflammation or rhinitis and start afresh.
Recent workers with pollens come near the truth in describing hay fever as an anaphylaxis. Right here my conception of the lesion of hay fever as an urticaria fits into the picture and brings us one step nearer to an understanding of the disease; for where is there a prettier example of anaphylaxis than those very hives with which long ago I compared the lesion of hay fever?
Since Bostock first described hay fever in 1816, hundreds of physicians have looked at thousands of patients, but, as far as I can discover, there was just one observer besides the modest author of this book who recognized the urticarial nature of the lesion of hay fever. This was Dr. Gueneau de Mussy, to whom we will devote the next chapter.
The Cause Behind the Lesion. All clinicians agree that there are two elements in the hay fever problem,—first, the irritant; and secondly, the abnormal sensitiveness of the patient. All are fairly well agreed as to the irritants, pollen and dust; but what makes the patient sensitive? This is still the dark side of the subject. Among the many theories, two seem to deserve further study and will be considered in the chapters on Hay Fever as Gout and Hay Fever as Anaphylaxis.