Hay Fever

HAY FEVER, an allergic disease observed in individuals with heightened sensitivity to certain types of flower pollen - pollens (Pflanzenpollen). H. f. was first described by the English physician John Rostock, who in 1819 reported to the London Medical Society his own history of the disease, which received the name of summer catarrh of Rostock. In 1873, Blackley demonstrated that the disease is associated with the action of certain types of flower dust found by him in the air, which, when it reaches the conjunctiva and nasal mucosa, causes conjunctivitis and rhinitis in some individuals. Blackley and later Dunbar and others also found that in patients with H. f., an increased sensitivity reaction to pollens is given not only by the nasal mucosa and conjunctiva, but also by the skin, and Schittenhelm, Weichardt and others drew attention to the similarity of H. f. with the phenomena of anaphylaxis. H. f. occurs with varying frequency in different countries depending on climate, flora and other factors. The statistical data available in the literature are most often not official materials of daily morbidity records by health authorities, but represent the results of sporadic studies specially undertaken by individual organizations or authors and naturally do not fully meet the requirements for accurate statistical data. In North America, there are up to 1,250,000 sufferers from H. f. (1% of the population). In mountainous Switzerland, the corresponding figures amount to only 8.3^0/_0P, with morbidity in cities being 8%o and in villages 1.3%o. The higher morbidity in cities (Rehsteiner) is explained by the intermittent contact of city dwellers with pollens, which sensitizes more strongly than the constant contact with pollens experienced by the rural population. As for the heredity of H. f., it is apparently only the ability that is inherited, under certain conditions, with longer or shorter exposure to the allergen (pollen), to acquire increased sensitivity to pollens. In particular, patients with H. f. usually do not get sick before the age of 10 years, i.e., increased sensitivity is not congenital; thus, along with certain genotypic features, the prolonged action of pollens is also required for the manifestation of H. f. The sensitivity of patients in the vast majority of cases is not strictly specific to any one type of flower pollen. The pathogenesis is not sufficiently studied at present. There are a number of theories, of which the most generally recognized considers the increased permeability of mucous membranes and skin to allergens as the pathogenetic basis of allergic diseases. The belonging of pollen to one or another type of flower dust does not affect the nature of the process and the clinical picture, the features of which are determined primarily by hereditary-constitutional factors; under otherwise equal conditions, the intensity and duration of the patient's contact with pollen also play a role. Skin tests with pollens in H. f. patients reveal a qualitatively altered pathological reaction compared to healthy individuals, which indicates that the basis of the process goes beyond the lesions of the conjunctiva and nasal mucosa that characterize the clinical picture of H. f. For a long time, proteins were considered the active ingredient in pollens, but the work of Grove and Coca, who showed that the removal of proteins from pollens does not affect the nature of the reactions they cause in experiments and in H. f. patients, has shaken this position. The clinical picture of H. f. is characterized mainly by a combination of conjunctivitis, rhinitis and often accompanying asthmatic type dyspnea. The most constant components of the clinical picture - conjunctivitis and rhinitis - appear simultaneously or sequentially. The patient complains of a sensation of a foreign body, burning sensation in the area of the eyelids, photophobia, attacks of sneezing and lacrimation; the conjunctiva is often hyperemic. After a few days, the conjunctivitis sharply intensifies, the eyelids swell, lacrimation decreases; a thick mucus begins to be secreted from the conjunctiva, the patient complains of sharp stabbing pains and increased pressure in the eyes. Both eyes are more often affected, but the degree of involvement may vary. The nasal mucosa is hyperemic, secretes an abundant watery discharge, the patient complains of burning and stabbing pains in the nose, exhausting attacks of sneezing that occur or intensify when going outside, opening windows, etc. The disease lasts the entire "season (up to six weeks). Gradually, the mucous membranes of the nasopharynx, trachea and bronchi become involved in the process. A hoarse voice appears, unpleasant sensations in the pharynx, and finally asthmatic attacks, which most often occur in the evenings and do not differ in course from attacks of bronchial asthma in the narrow sense of the word. The general condition of the patient sharply worsens. The patient is lethargic, passive, complains of general weakness, insomnia, sensation of heat throughout the body and cold in the extremities. The temperature may remain normal, but most often it rises, reaching 39° at the height of an attack, and has a remittent character. The pulse is small, generally accelerated, during the attack slowed down, very labile. The first attacks are often abortive, poorly expressed and not always recognized. In young individuals, the clinical picture of hay fever is often limited to conjunctivitis and rhinitis, in the elderly, asthmatic phenomena usually also join. Along with the clinical picture presented, the history is of great importance for diagnosis, in which indications are often found of the connection of the disease with the action of one or another pollen. Skin tests with pollens are also of great diagnostic value, with the help of which it is possible to differentiate individual cases of H. f., sometimes specific with respect to certain types of flower dust. The technique of the test consists in applying a tiny amount of aqueous pollen extract to a small skin wound on the flexor surface of the forearm in a drop of strong alkali. In a positive reaction, which appears only in sensitized individuals, a white wheal with a reddish zone around it appears at the site of the skin incision after a few minutes, causing itching in the patient. The same results are obtained with the intracutaneous test. The tests are performed not with one, but with several pollens, usually starting with those for which there are indications in the history and whose presence in the air at this time, in this locality, can be expected. Usually, as already indicated, patients give reactions to several pollens. It should be noted that skin reactions with pollens in H. f. are more often positive than reactions with corresponding allergens in other allergic diseases. Dunbar proposed for hay fever instead of skin tests the introduction of pollen extracts into the conjunctival sac, which also leads to a characteristic reaction. The treatment of H. f. could consist in isolating the patient from contact with the corresponding pollens, which is easily achieved by changing the patient's place of residence or by his departure from the given locality during the H. f. season. However, with the frequency mentioned above, this measure is practically unfeasible. Proceeding from the fact that in a number of cases after a certain period of time (sometimes several years) spontaneous healing occurs, the practice of treatment and prevention of H. f. is based on active desensitization to pollens on the same principle as desensitization in other allergic diseases with respect to allergens. Depending on the results of skin tests, for desensitization in each individual case, either a monovalent extract of a specific pollen, or a polyvalent extract from different pollens, or a series of monovalent pollens are used. Desensitization is carried out by subcutaneous injections of pollen extracts in large dilutions under the skin. Usually, they start with the first dilutions that give the patient with H. f. a weakly positive reaction, gradually increasing the concentration with each subsequent injection. Walker starts with the introduction of 0.15 cm³ in a dilution of 1:10,000, conducting a course of 14 injections with intervals between injections of 5-8 days, reaching 0.25 cm³ in a dilution of 1:100 at the last injection. In America, Pollenantigen'bi from Lederle is mainly used, dosed in units that are equivalent to 0.000001 g of pollen. The course is 16 injections, starting with 2.5 units and ending with 1,500 units, with intervals between injections of 48 hours. The course of injections usually begins 2-3 months before the start of the corresponding H. f. season and ends at its beginning. Some authors continue the injections (1 time per week) until the end of the season. Since desensitization is not permanent, it is necessary to resort to this treatment annually, and in stubborn cases, continuous treatment with injections for 2 years, regardless of the season, is also recommended. Along with injections, some authors (Mackenzie) use pollen extracts (from 0.01 to 10 mg) locally on the nasopharyngeal mucosa.

Pollens, as has been experimentally proven, are not antigens in the strict sense of the word. Along with treatment with mono- and polyvalent pollen extracts, Storm van Leeuwen also recommends non-specific tuberculinotherapy. Attempts at passive immunization with the serum of patients do not lead to positive results. Nevertheless, Denbar proposed for the treatment of H.F. Pollantin, which is a serum of horses immunized with pollen toxins. Pollantin is applied locally and under the skin. The latter method is unsafe (Pollantin is poisonous). Weichardt proposed for the treatment of H.F. Graminol-serum of cattle, obtained from animals during the flowering period of grasses, freed from salts and dried. It is used in the same way as Pollantin. The effectiveness of treatment with all the methods mentioned is far from constant; some authors recommend the local application of optochine, adrenaline, atropine, and intravenous injections of calcium chloride. The prognosis in hay fever is generally favorable.