Idiosyncrasy
Idiosyncrasy comes from
Greek ιδιοσυγκρασία "a peculiar temperament," "habit of body" (
idios "one's own" and
sun-krasis "mixture"). It is defined as a structural or behavioral characteristic peculiar to an individual or group.
The term can also be applied to
symbols. Idiosyncratic symbols are symbols that may mean one thing for a particular person, as a blade could mean war, but to somone else, it could symbolize a
knighting.
Idiosyncrasy defined the way physicians conceived
diseases in the nineteenth century. They considered each disease as a unique condition, related to each patient. This understanding began to change in the 1870s, when discoveries made by researchers in Europe permitted the coming-to-existence of a 'scientific medicine', a precursor to the
Evidence-Based Medicine that is the standard to practice today.
In contemporary medicine (as of 2006), the term denotes a non-immunological
hypersensitivity to a substance, without connection to pharmalogical toxicity.
[Roche Lexikon Medizin, 5th edition (online version, German)].
Idiosyncratic stresses here the fact that other individuals would react differently, or not at all, and that the reaction is an individual one based on a specific condition of the one who suffers it. Most commonly, this is caused by an
enzymopathy, congenital or acquired, so that the triggering substance cannot be processed properly in the organism and causes symptoms by accumulating or blocking other substances to be processed. An idiosyncrasy causing symptoms like an allergy is also called
pseudoanaphylaxis .
In
psychiatry, the term means a specific and unique mental condition of a patient, often accompanied by
neologisms.
In
psychoanalysis and
behaviourism, it is used for the personal way a given individual reacts, percieves and experiences a common situation: a certain dish made of meat may cause nostalgic memories in one person and disgust in another. These reactions are called
idiosyncratic.