The experiments of Blackley justify the belief that the cause of the early form of hay fever, which prevails in England, is to be found in the pollen of a number of plants, especially grasses and grains, which bloom in the late spring and early summer, while those of Marsh prove conclusively that the Ambrosia artemisiæfolia, or Roman wormwood, is certainly one, and probably the chief, cause of the American or autumnal variety of the disease.
GEOGRAPHICAL DISTRIBUTION.—Both varieties of hay fever prevail in the United States, but the late variety is much more frequent, and may be regarded as peculiar to this country. The distribution of the early form of the disease is much more extensive. It is quite frequent in Great Britain, and, according to our present knowledge, it extends over France, Belgium, Holland, Switzerland, Italy, Russia, and in the plains of India (but only among foreign residents). Further investigations will probably show that it also extends over the other temperate regions of Europe. As before stated, the autumnal form is confined to the United States, where it prevails much more extensively than was formerly supposed. Commencing in Florida, where it is quite rare, it extends northward up to Eastport, Maine. Its northern border is defined by Wyman15 as follows: "From the St. Croix, south of Houlton in Maine, or about the line of 600 feet elevation above the sea-level, the line of exclusion turns eastward, following approximately the border of the elevation just mentioned, excluding the interior lakes of Maine, which are about 1000 feet above the sea, and, descending toward the south, strikes the White Mountain region at its northern portion. Thence, turning toward the St. Lawrence River and running along the height of land which divides the waters falling into the Atlantic from those falling into the St. Lawrence, parallel to the St. Lawrence, it strikes that river north of Lake Champlain." Thence along the southern border of the Great Lakes to the south of the island of Mackinaw, between Lakes Huron and Michigan. "It then crosses the lake and runs north of Lake Winnebago to St. Paul, Minn., leaving the Lake Superior copper-regions beyond its influence." From this point the line is undetermined, but there is evidence to show that the disease occurs in Colorado. The statement of previous authors, that the disease does not prevail in California, is confirmed by a statement recently made to the writer by Hatch, secretary of the Board of Health of that State, who adds that several parties have removed there to avoid the disease. Southward, the line runs along the Mississippi River to New Orleans, where the disease prevails. The southern and eastern borders are the Gulf of Mexico and the Atlantic Ocean.
15 Op. cit., p. 63.
SYMPTOMS AND COURSE.—No better description of an attack of the autumnal form of hay fever has ever been written than that of Wyman, who, being himself a sufferer from the disease, has had exceptional opportunities for studying it in all its details. I therefore extract the following from his work:16
"All the cases agree in the time of annual return, about the 20th of August, varying but a few days from this date in different years. By some individuals it is believed to be remarkably punctual, being first noticed on precisely the same day of the month, and, it is even asserted, at the same hour of the day. It is first perceived as a slight itching in the palate and in all parts about the roof of the mouth, soon followed by similar sensations, apparently in the Eustachian tube, extending from the throat into the ears, and inducing the sufferer to attempt relief by swallowing and by rubbing his tongue against the back part of the hard palate, and by pressing and rubbing the external orifice of the ear to give motion to the parts within. There is often a sense of tension about the forehead, especially over the eyes in the region of the frontal sinuses. In a day or two the nostrils are affected; there is irritation of the lining membrane, sneezing, and a stuffing and obstruction of the nostrils. This obstruction is peculiar; it occurs in paroxysms of short duration, one or both nostrils becoming suddenly obstructed, and in two or three minutes as suddenly relieved; at other times the obstruction is more prolonged. But, however complete, it is in many individuals almost immediately relieved by active exercise, rapid walking, leaping, or any movement indeed which gives warmth to the extremities.
"At first these attacks occur only in the morning or on first rising; as the disease advances they occur later in the day, but still in short paroxysms. At this stage the discharge from the nostrils is limpid and almost free from mucus; it is often very copious, especially during or immediately following attacks of sneezing. Holding down the head is often accompanied by a rapid dropping of the same fluid without sneezing. With this trouble in the nostrils come watering of the eyes and itching along the edge of the lids and in the conjunctivæ generally, but most at the inner corners. This irritation occurs also in paroxysms of a few minutes' duration. It is so intense that it is difficult for the sufferer to refrain from rubbing the eyeballs violently, which soon relieves them, notwithstanding that such treatment increases the turgidity of the vessels until the whole conjunctival surface is of a nearly uniform red. The eyelids are swollen, their edges red and inflamed; the small glands are also inflamed, and in some cases pustules or styes form and break, leaving an excoriated surface which heals slowly. The whole face is often red and swollen, especially in the morning. The senses of taste and smell are much impaired, in some cases almost abolished; and at times there is partial deafness, with a sense of obstruction of the internal ear. The lining membrane of the external tube is sometimes much irritated, even to the extent of producing a thin discharge, without evidence of the irritation extending to the tissue beneath. Swallowing is interfered with, especially when the nostrils are so obstructed as to prevent the perfect motion of the parts necessary to this act. The lining membrane of the mouth, tonsils, and pharynx partakes of the general irritation, and becomes red; and sometimes there is soreness of the throat. The lips become dry, cracked, and swollen. The skin is easily irritated and excoriated, and the excoriations are not so readily healed as in health. Many also suffer from itching of the skin, especially of the scalp, back, and chest, at times accompanied by a slight papular eruption. During some portion of this period there is chilliness, or rather sensitiveness to cold; more or less pain or sense of oppression in the head; the appetite diminishes; there is lassitude and weakness, the skin hot and dry, with other signs of a febrile movement.
"Toward the end of the second week to these symptoms are added irritation of the membrane lining the air-tubes; a frequent and dry cough, commencing with a sense of tickling in the upper part of the windpipe, but little relieved by the cough or only after long coughing; and the expectoration of a small quantity of transparent, glairy mucus. The severity of these bronchial symptoms depends much upon the condition of the atmosphere: if dry and dusty, the cough is much worse; dampness and a rainstorm give relief.
"During the third week the affection of the lungs gradually increases; the cough, still with very little expectoration, is more troublesome, especially in the night, sometimes compelling the patient to spend an hour or two sitting up, and not infrequently is spasmodic in its character, producing convulsive retching or even vomiting.
"The disease may now be assumed to be at its height. It is in this stage also that in some cases asthmatic symptoms appear, and, although they are sometimes severe, are not long continued. At the end of the third week the catarrhal symptoms diminish, the tickling of the fauces ceases, the eyes and nose improve; but the cough is apt to continue longer, and the heart's action is easily accelerated by exercise, and the pulse is sometimes intermitting. The skin is dry and warmer than natural.
"During the fourth week in September these symptoms gradually diminish, and by the end of September or the first frost are nearly gone, leaving weakness and a more or less altered state of the mucous membrane of the air-tubes, the effect of the prolonged irritation, from which the patient, if otherwise in good health generally soon recovers."