noun
idiosyncrasy; allergy
Medical term for an individual's unusual or allergic reaction to a substance. Used in clinical contexts.
この薬は特異質反応を起こすことがある。
This medicine can cause an idiosyncratic reaction.
患者の特異質を考慮して治療法
Choose a treatment method considering the patient's idiosyncrasy.
体質 refers to one's general constitution or predisposition, whereas 特異質 specifically denotes an unusual or allergic idiosyncrasy.
Compound of 特異 (とくい, 'peculiar, unique') and 質 (しつ, 'quality, nature'). The exact historical derivation is uncertain; the term is used in modern medical Japanese.