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Food allergy
Editorial FOOD
ALLER(:T
There is perhaps no field of medicine in which more divergent views arc held than in that of allergy to foods. It, would seem worth while, therefore. to outline some procedure hp which a beHer understanding of the subject coul(l be obtained. One difficulty in the field is that most manit’estations ascribed to food allerg) are common to many other condit,ions, actual or immaginary. dtt,itudes and heliefs regarding foods, whether or not they are based on physiologic effects, dcpendent on or independent of psychic influences, stun, in pdrt at least, from centuries of lore, national, religious, racial, rc,gional--and medical. The manifestations claimed by some to be of allergic origin are not, only numerous but extremely diverse, so much so that, there is hardly an ache or a twinge that may not fall within the purview of the allergist. The nntuw of these reactions, therefore, may give no clue as to the role played b,v allergy. Tndirect test,s can bc I’Pgarded as valid only after they have been shown to he so in instances of prfJt’f’(l allergy to foods. This rernains to be done. Therrforc. t!lr use of procrdurcs such as the leukopenic indes, changes in the number of c*iI~cnlating eosinophils. or skin tests cannot give US the information ~1 need. Although it is clearly not sufficient to say that an allergic mechanism operates because ii certain reaction follows the ingestion of one or more foods, the demonstration of a cause and effect relationship is nevertheless essential. This is the first step-a difficult one because no procedure can be relied upon in which the patient suspected o-f food allergy can identify the substance undet~ ttst by taste, smell, texture, or color. The food should he completely disguised by some means or other, and perhaps it is best given in capsules or bp stoma,c h t,ube. Other foods given in the same manner should fail to cause any rea.ction. E’urthermore, the reaction should be consistently reproducible as regards typts and the time of its occurrence. Once these criteria have been met, a cause anal effect relationship would appear to have been established, and it would seem Such a conclusioii reasonable to ascribe the reaction to an allergic mechanism. is not st,rictly logical, however, because a cause and eff’ect relationship is Ilot solely peculiar to allergic mechanisms, however match wtl as allergists may SW fit to regard it so. According to immunologic theory, allergic reactions arise from the intcbraction of the allergen with antibody fixed to tissue or in close proximit,y to il. (Year evidence for an allergic mechanism is readily found in many patients with asthma and hay fever, and it would appear reasonable to find similar eridellcci of an allergic mechanism in a patient who is allergic to one or more foods. 1 I evidence should bc forthcoming to present-day theory requires modification, show that the theory in modified form is valid. I-low is an allergic mechanism to be demonstrated in the patient whose fatigue is attribllted to allergy to COH563
564
THE
JOURNAL
OF
ALLERGY
starch? Skin reactions to corn may be negative and skin-sensitizing antibody absent. It would appear impossible at present to carry the investigation of such a case beyond the attempt to demonstrate a cause and effect relationship. Nevertheless, much can be done on this problem. A close study of a relatively smaI1 number of carefully selected patients having indubitable allergy to foods, as judged by the type of criteria given above, would go far toward clarifying the subject and giving us a useful understanding of allergic reactions to foods. Such a study might include, in addition to those studies mentioned, quantitative tests for skin sensitivity and skin-sensitizing antibody, determination of the dosage required to produce a reaction, the interval required before the reaction takes place, the duration of the reaction, and something might also be learned concerning the behavior of the white cells, the eosinophils, and the value of x-ray studies. All this is tantamount to saying that we must learn far more about what appears to be familiar before we can effectively tackle the The experience gained could then be problems that face us in food allergy. applied to other patients in whom the role played by allergy can only be a matter of conjecture today. F. C. LOWELL
ALLER(:T
There is perhaps no field of medicine in which more divergent views arc held than in that of allergy to foods. It, would seem worth while, therefore. to outline some procedure hp which a beHer understanding of the subject coul(l be obtained. One difficulty in the field is that most manit’estations ascribed to food allerg) are common to many other condit,ions, actual or immaginary. dtt,itudes and heliefs regarding foods, whether or not they are based on physiologic effects, dcpendent on or independent of psychic influences, stun, in pdrt at least, from centuries of lore, national, religious, racial, rc,gional--and medical. The manifestations claimed by some to be of allergic origin are not, only numerous but extremely diverse, so much so that, there is hardly an ache or a twinge that may not fall within the purview of the allergist. The nntuw of these reactions, therefore, may give no clue as to the role played b,v allergy. Tndirect test,s can bc I’Pgarded as valid only after they have been shown to he so in instances of prfJt’f’(l allergy to foods. This rernains to be done. Therrforc. t!lr use of procrdurcs such as the leukopenic indes, changes in the number of c*iI~cnlating eosinophils. or skin tests cannot give US the information ~1 need. Although it is clearly not sufficient to say that an allergic mechanism operates because ii certain reaction follows the ingestion of one or more foods, the demonstration of a cause and effect relationship is nevertheless essential. This is the first step-a difficult one because no procedure can be relied upon in which the patient suspected o-f food allergy can identify the substance undet~ ttst by taste, smell, texture, or color. The food should he completely disguised by some means or other, and perhaps it is best given in capsules or bp stoma,c h t,ube. Other foods given in the same manner should fail to cause any rea.ction. E’urthermore, the reaction should be consistently reproducible as regards typts and the time of its occurrence. Once these criteria have been met, a cause anal effect relationship would appear to have been established, and it would seem Such a conclusioii reasonable to ascribe the reaction to an allergic mechanism. is not st,rictly logical, however, because a cause and eff’ect relationship is Ilot solely peculiar to allergic mechanisms, however match wtl as allergists may SW fit to regard it so. According to immunologic theory, allergic reactions arise from the intcbraction of the allergen with antibody fixed to tissue or in close proximit,y to il. (Year evidence for an allergic mechanism is readily found in many patients with asthma and hay fever, and it would appear reasonable to find similar eridellcci of an allergic mechanism in a patient who is allergic to one or more foods. 1 I evidence should bc forthcoming to present-day theory requires modification, show that the theory in modified form is valid. I-low is an allergic mechanism to be demonstrated in the patient whose fatigue is attribllted to allergy to COH563
564
THE
JOURNAL
OF
ALLERGY
starch? Skin reactions to corn may be negative and skin-sensitizing antibody absent. It would appear impossible at present to carry the investigation of such a case beyond the attempt to demonstrate a cause and effect relationship. Nevertheless, much can be done on this problem. A close study of a relatively smaI1 number of carefully selected patients having indubitable allergy to foods, as judged by the type of criteria given above, would go far toward clarifying the subject and giving us a useful understanding of allergic reactions to foods. Such a study might include, in addition to those studies mentioned, quantitative tests for skin sensitivity and skin-sensitizing antibody, determination of the dosage required to produce a reaction, the interval required before the reaction takes place, the duration of the reaction, and something might also be learned concerning the behavior of the white cells, the eosinophils, and the value of x-ray studies. All this is tantamount to saying that we must learn far more about what appears to be familiar before we can effectively tackle the The experience gained could then be problems that face us in food allergy. applied to other patients in whom the role played by allergy can only be a matter of conjecture today. F. C. LOWELL