An Address on THE TREATMENT OF ALLERGIC DISEASES IN GENERAL PRACTICE

Abstract

An individual is said to be allergic when he manifests an exaggerated susceptibility to substances innocuous to normal persons in the amounts commonly encountered. This hypersensitiveness or allergy on the part of the sufferer to many, usually harmless articles commonly con tained in his diet or environment manifests itself in such numerous and apparently diverse conditions as asthma, hay fever, eczema, urticaria, and migraine, as well as in an ever-increasing host of minor affections. At first it was thought that only protein substances could act as allergens or originators of these reactions, but recent observations have shown that many non protein factors, such as carbohydrates, drugs, and even physical agents, can lead to identical reactions. When we analyse these allergic responses we find that they usually originate in one of two ways, either as a definite in heritance of the predisposition to manifest a specific hypersensitiveness of some type to some substance, or acquired as the result of tissue damage or excessive irrita tion. During childhood the chief aetiologic factor is the hereditary tendency, which can be demonstrated in from half to two-thirds of all cases ; but in the majority of adults post-natal factors have been particularly severe and constant?for example, the continual association with a particular allergen either by occupation or by environment, combined possibly with extensive tissue trauma. Such a mode is exemplified in cases in which asthma has followed such lung damage as pneumonic processes complicating infections, in which a succeeding sensitization occurs to feather pillows or horsehair bedding on which the patient has lain during the illness, or in cases in which paroxysmal rhinorrhoea follows some nasal infection upon which a sensitization to dust, animal emanation, or face powder later develops. Such a division of cases, if possible, into primary (or hereditary) and secondary (acquired, or post traumatic) is of great importance in determining the ca'usa tive allergen, as the latter group is practically always inhalant or occupational in nature. For this reason a thorough history of the time and mode of onset is essential. Allergic diseases have several characteristics in common. They are essentially periodic in nature, with apparent intervals of complete freedom. Symptoms generally have their onset during the night, or are most distressing during those hours. They have their maximum age at onset during childhood or adolescence?with the exception of hay fever?and each manifestation appears to have definite sex and seasonal variations. Besides the common history of allergic complaints obtainable in relatives or offspring, the patients usually give an account of some other allergic manifestation in their present or previous history. Finally, allergic diseases are greatly affected by varied states of health of the sufferer, and especially by indigestion, menstruation, and pregnancy ; by intercurrent disease such as fevers, exanthemata, or following opera tions ; by emotion, excitement, or exhaustion ; or by a change of climate, locality, altitude, or environment. Their treatment involves a very definite routine, so that reliance on one therapeutic agent for all cases, irrespective