Idiosyncrasy

IDIOSYNCRASY (from the Greek idios-own and synkrasis-mixing), literally-unique composition of juices or unique constitution; a concept that is not sufficiently clear. In common understanding, it denotes a unique individual sensitivity, individual predisposition to heightened reactions to minimal, usually almost indifferent effects on the body or irritations. This primarily includes cases of urticaria following the ingestion of substances such as lobsters, oysters, strawberries, and even cow's milk, egg white, pork meat, etc. The so-called hay fever should also be included in this category, which manifests as characteristic attacks in certain, especially predisposed people at a certain time of year-during the period of grass flowering. The attacks are expressed as redness and swelling of the mucous membranes of the eyes, throat, and nose, sneezing, coughing, etc. In some cases, the milder symptoms described may be accompanied by a pronounced picture of asthma. Similar phenomena are sometimes observed in persons caring for horses, when in a stable. The so-called medicinal idiosyncrasies (increased sensitivity to certain medications-quinine, iodine, bromine, iodoform, antipyrine, etc.) belong to the same group of disorders. Finally, serum sickness (see Anaphylaxis) can be fully treated from the same point of view, taking into account that the latter develops under appropriate conditions in far from all people, but only in approximately 1/10 of subjects. Idiosyncrasy is a constitutional state, although not always congenital (changes in constitution with age). In a number of other cases, however, idiosyncrasy is hereditary (for example, idiosyncrasy to quinine). The pathogenesis of idiosyncrasy is unknown. Usually, idiosyncrasy is treated in the context of the doctrine of anaphylaxis, i.e., sensitization of the body by one means or another with minimal amounts of foreign protein, and in cases of food idiosyncrasy, this is obviously carried out through the digestive tract. This is understandable if we consider that part of the foreign protein introduced per os can pass through the intestinal wall into the blood in an undigested form. To understand the pathogenesis of hay fever, it is necessary to assume sensitization with plant protein (flower pollen) through the respiratory tract. The possibility of this is fully confirmed by the following data of both experimental and clinical nature: in Friedberger's experiments, classical anaphylactic phenomena occurred in guinea pigs not only after injection of horse serum, but also after inhaling it in an atomized form, and among other things, such inhalation gave sensitized guinea pigs inflammatory foci in the lungs (so-called pulmonary reaction), by analogy with the Arthus phenomenon on the skin with skin sensitization. On the other hand, an extract from flower pollen, when injected subcutaneously, causes a characteristic attack in people predisposed to hay fever at any time of year, while others under the same conditions show no reaction at all. In a similar way, the pathogenesis of "asthma of grooms" (inhalation of traces of horse protein) is interpreted. Medicinal idiosyncrasies are somewhat more difficult to explain, since here we are dealing with substances that do not possess antigenic, resp. sensitizing properties, i.e., incapable of producing antibodies, which, according to common views, is necessary for the development of anaphylaxis. The following mechanism of body sensitization is assumed here. As shown by Obermayer and Pick, proteins under the influence of certain chemical processing seem to lose their species specificity. One can therefore assume that iodine, as well as a number of other medicinal substances, causes denaturation of proteins, and the body begins to regard iodinated and other denatured protein products as foreign proteins, with respect to which sensitization becomes possible. From this point of view, medicinal idiosyncrasies could be interpreted as sensitization to the individual's own proteins, denatured under the influence of certain substances, in favor of which the following fact from the field of passive anaphylaxis is cited among other things: animals that received serum from a person susceptible to a particular chemical substance themselves acquire increased sensitivity to the same substance (Klausner, Bruck and others). This question, however, cannot yet be considered resolved. Moreover, one must think that an individually different resistance of the autonomic nervous system, which is known to react sharply in anaphylactic shock and anaphylactoid conditions, plays a significant role here. In the very recent past, Hans Much in his book "Idiosynkrasie" has categorically spoken against the identification of idiosyncrasy with anaphylactoid conditions, arguing with a number of considerations, among others the following: 1) anaphylactoid conditions presuppose prior sensitization, which cannot be said about idiosyncrasy; 2) idiosyncrasy can relate the body to substances that do not cause anaphylaxis, for example, to medicinal ones like quinine, iodine, etc., and even under conditions where there is no question of introducing any foreign sensitizing substances into the body (such is, for example, idiosyncrasy to climatic factors). Much explains non-congenital idiosyncrasy by constitutional shifts on the basis of lipoid changes. Psychic idiosyncrasy should be understood as the individual peculiarity of a given person to experience and react to given stimuli not as is usually the case; thus in idiosyncrasy the exceptional peculiarities of a given personality are revealed, manifesting in certain inclinations or aversions. Biographical analysis usually allows one to uncover the causes of idiosyncrasy in each specific case.