There is a class of cases of difficulty of breathing allied to asthma and often called by that name, the study of which throws light on the origin and the relief of neurotic asthma. These cases are usually accompanied by such a sense of oppression on the chest that breathing becomes labored and, to some {374} extent at least, the accessory muscles of respiration have to be called into play. The most typical cases are connected with the mental influence produced by the presence of some particular animal, the cat being the most frequent and the horse not rare, or with emanations from these animals, when there seems to be some physical nexus between the animal and the symptoms.

Cat Asthma.—The symptoms associated with cats are rather common, and they occur at the sight or touch of the animal, but may be the result only of its presence which in some way the patient is able to recognize without sight of him. Shakespeare's expressions in a number of places, such as "I could endure anything before but a cat" and "some that are mad if they behold but a cat," shows that the affection was commonly recognized at that time and that the reason for it was considered unknowable, for Shakespeare says, "There is no firm reason to be rendered why he cannot abide ... a harmless necessary cat."

Dr. Byron Bramwell in his "Clinical Studies," Vol. I, page 107, has an interesting paragraph with regard to these curious asthmatic conditions which develop in the presence of animals of various kinds. He sums up many of the curious features of this affection as reported by various good observers. Many more people than we would be apt to think are affected by it. He says:

In some persons the smell of a horse or of a cat produces an attack of asthma. Some years ago I repeatedly saw a young gentleman who invariably had an attack of asthma if he went near a stable or a horse. He was so susceptible that he was unable to drive in a cab or a carriage; when traveling from place to place, while sending his traps from the station to the hotel in a cab, he himself was obliged to walk.

Dr. Goodhart mentions a similar instance which occurred in the practice of Prof. Clifford Allbutt. Dr. Goodhart also mentions a remarkable case of "cat asthma":

I have known of two cases of cat asthma. In one of them the existence of cats is the bane of life, for before accepting an invitation she is obliged first to ask, "Is there a cat?" [Footnote 32] An attack of urticaria and coryza followed by asthma has been noticed to come on within ten minutes of having stroked a cat. At other times, sitting in a room in which there was a cat, without any actual contact with it, was sufficient to produce a bad attack, beginning within ten minutes of entering the room.

[Footnote 32: A case of this kind came under observation as this book was nearly ready for the press. The patient, a young woman in an office, had to refuse a vacation with a wealthy friend in Florida, because she knew that friend could not be separated from her pet cats, five in number, and the patient would have been intensely miserable were she near them, so that even the joys of Florida in the winter did not make up for the constant, intolerable discomfort they would have caused her.]

There are two forms of this intolerance of a cat. One of them takes on the character of a dread and is discussed in the chapter on Dreads. The other is accompanied by dyspnea or asthma with a sense of discomfort and tightness of the chest that cannot be overcome. It is not merely an imagination, for sometimes even when they cannot see the cat, or at times when friends have been careful to exclude cats from the room, these people become impressed with the idea that a cat is near and a search usually shows that their impression is true, though just what was the means through which they came to know it is difficult to understand.{375}

Dr. Weir Mitchell's review of the subject of "Cat Asthma and Allied Conditions" in a paper read before the Association of American Physicians brought out many curious details. There is no doubt about the power to recognize the presence of the unseen cat. Besides the respiratory oppression, some patients develop urticarial lesions and occasionally even conjunctivitis and a catarrhal condition of the nasal mucous membrane. These seem to be due to the direct irritant effect of animal emanations. As the symptoms of rose cold or hay fever have sometimes developed after the sight of an artificial rose, or even, it it said, the picture of a hay field, so, in some of these cases, the sight of a picture of a cat has produced at least some of these symptoms. Probably the most interesting feature of the affection is that the large cats, the tiger and the lion, do not have any effect on the patient. There seems to be no doubt, then, that the mind plays an important role in the matter and that relief must be secured through mental influence.

In some of these cases a careful searching of the past of the patient will show that there has been some terrifying incident connected with the cat. In one case in my own experience the patient's earliest recollection, and the first time that death was brought home to her, was when a favorite bird was killed by a cat. Ever after that she had a horror of the animals, the family cat had to be disposed of, and her family never had another. She used to suffer from a severe dyspnea at the sight of a cat and was sure that she could recognize its presence without having seen it. She mentioned a number of occasions on which that had been true. The very idea of living where a cat could come near her was appalling. She was sure that she was even waked by the mere propinquity of a cat if by any chance one got into her room at night, though without any noise.

A change in her material circumstances compelled her to teach in private families. Under these circumstances her cat detestation made difficulties for her. I suggested, since she had had no feeling toward cats before the bird incident, that probably her symptoms were due to suggestion and an acquired habit of mind and that she might by discipline overcome them. She was sure that would be impossible. With determined effort, however, and practice in withstanding her feelings in the presence of cats she finally learned to overcome practically all of her feelings so that though it still requires an effort she can even pick up a cat and stroke it. I have had several other patients with less marked forms of the affection who have by self-discipline overcome their feelings to a great degree. It is always well to search the past of these patients in order to find out whether there may not be a dominant idea derived from some unfortunate experience, which acts as an auto-suggestion in the production of their symptoms of constriction of the chest and sometimes even the recurrence of the swelling of the mucous membrane of the nose that produces difficulty of breathing. Whenever this can be found, contrary suggestion can be given and the patients can be persuaded to try, by frequently repeated auto-suggestion, to relieve themselves of the trouble.

Occasionally these curious manifestations of a catarrhal or asthmatic character in the presence of cats occur in people who like cats. Dr. Taylor in his "Types of Habit Neuro-Psychoses" published in the Proceedings of the Massachusetts Medical Society, 1896-98, tells the story of a young woman in whom he saw conjunctivitis developing while she was fondling a cat. In many cases {376} besides the hyperemia of the nose and of the respiratory mucous membrane generally there is marked injections of the ocular conjunctiva. It is rather difficult to understand the phenomena of asthmatic attacks in connection with cats and other animals in terms of a habit formed, because at some time asthmatic or hyperemic manifestations occurred in association with the handling of these animals and that then, somehow, suggestion works to reproduce the same symptoms in the presence of the animals later; but this is undoubtedly the only rational explanation that we have for many of these cases. It represents the most helpful explanation, so far as treatment is concerned, for by means of suggestion either in the waking state or in the first stage of hypnosis, in many cases relief can be brought to these patients. Repeated profound hypnotism is a vaunted remedy for these conditions in the hands of professional hypnotists, but serious physicians who have tried hypnotism do not recommend it. It helps for a time but relapse follows. Only continued suggestion and a carefully cultivated habit of self-discipline and control succeed.

Horse Asthma.—The cases of dyspnea in connection with horses are not less interesting. Occasionally, even when all aversion is absent, emanations from horses are capable of producing a curious effect on certain individuals. How much of this is psychic is not clear. I was once consulted with regard to a patient who suffered from asthma whenever she went to a dance. It mattered not how careful she was in not exposing herself to night air, or in wrapping herself up warmly; invariably a few hours after her return home, she was wakened from sound sleep by an attack of difficult breathing that required the opening of windows and the use of the accessory muscles of respiration in order to satisfy her air hunger, and even then her symptoms were quite alarming to herself and her friends. At first, her asthma was thought to be due to sudden changes of temperature in going out into the air after the dancing, and various devices were tried to lessen the shock of the cold to the respiratory mucous membrane. None of them had any effect. Then it was thought that the dust of the ball-room made the difference and so she was forbidden to dance. After a time it was found, however, that if she went out in the evenings to social functions, whether she danced or not, or though she avoided completely being in dusty rooms or where many people were moving, she still had the attacks a few hours after she returned home.

Finally it was noted that these attacks of asthma also occurred on several occasions after she had been out riding during the day in a carriage. Then one evening after a rather long intermission free from attacks, in spite of directions and her fears, she went to a ball, but owing to circumstances went and returned by trolley instead of, as usual, in the family carriage. That night she had no attack of asthma. Experiments were made then and it was found that whenever she rode behind horses she suffered from an attack of asthma during the following night. The attack was evidently not due to suggestion. The story illustrates the necessity for carefully analyzing all the circumstances of an asthma patient and making sure that some one of these curious and unusual conditions are not at work, for if they are, the only possible curative treatment is by influencing the patient's mind, first by demonstrating the cause of the affection and then by training in self-control to reduce the reaction.{377}

Recently I have been consulted with regard to a physician who has developed in a rather curious manner a sensitiveness to the presence of horses. As an interne at a hospital during an epidemic of diphtheria he took a dose of diphtheria antitoxin for immunizing purposes. The amount injected was 750 units, the remainder of the dose of 1,500 units contained in the phial being given to the nurse who had charge of the cases. She suffered absolutely no ill effects, so that the manifestations in his case were entirely due to idiosyncrasy and not to anything in the serum itself. Within fifteen minutes after taking the injection the mucous membrane of his nose became so congested as to make it impossible for him to breathe through his nostrils and the mucous membrane of his soft palate was seriously disturbed in the same way. His face became much swollen, the edema affecting particularly his eyelids and his lips and hundreds of wheals appeared all over the body. Fortunately the edema did not affect the larynx, or the issue might have been fatal, or would surely have required intubation. His pulse became extremely rapid and weak, there was marked dyspnea, and whenever the patient sat up there was fainting or a distinct tendency to it.

Under active stimulation and elimination the symptoms rapidly passed off so that the only noticeable edema the next morning was in the eyelids and lips, which, however, also disappeared within twenty-four hours. Up to this time the physician had never been bothered by any tendency to hay fever or to asthma and there is no history of either of these affections in his family. Thereafter, however, though quite without his anticipating it, and, indeed, the first symptoms were incomprehensible, he became extremely sensitive to emanations from horses. When he rides behind a horse for some distance his conjunctivae become injected, the nostrils become congested and difficulty of breathing sets in with a sense of constriction of the chest. These subside as soon as he gets away from the presence of the horse and has washed himself thoroughly. He suggests that he has become sensitized to horse serum and, as it did not exist before his experience with diphtheria serum, he, of course, connects that incident with the present tendency. It is easy for such a case to have its real significance entirely missed and, of course, treatment by prophylaxis, the most efficient form, would then be out of the question.

Other Forms.—Apparently at times human emanations or some peculiarity of odor seems to influence asthmatic conditions. I have been told by a good observer—a physician—of two brothers who had an attack of asthma whenever they visited each other. At first this was attributed to something in the air or some other condition of the visit. After a time it was found to occur under varying circumstances, but that the one essential was the association with each other.

Treatment.—The more one knows about asthmatic conditions the more does it become clear that special study of individual cases is extremely important for any definite knowledge of the causation in a particular case. Without a knowledge of the cause the treatment is very unsatisfactory and in the meantime the unfavorable suggestion of the recurrence of the attacks acting upon the patient sometimes disturbs the general health. To remove this unfavorable influence must be the first care of the physician and then if the real cause can be found, favorable suggestion and modifications of the mode of life, with self-discipline and control of the mental attitude and of the {378} nervous system, may greatly aid in the reduction not only of the number of attacks and of the severity of the symptoms, but finally lead to complete eradication of the affection.

Mental control to some degree can be obtained and it has even been suggested that if the emanations from an animal cause physical symptoms, gradually increased dosage of them, beginning with very small amounts, that is, short periods of association with the animals in question, may gradually lead to the production of an immunity to them as it does even to the much more serious results of snake poison. Certainly some patients seem to have succeeded in bringing relief to themselves by this means and it is worth while remembering in the therapy of the affection, if for no other reason than the strong suggestion that goes with it.{379}