How to say "allergy" in Japanese

• アレルギーCommon
  noun, noun (suffix)The usual word for allergy in the medical sense, an abnormal immune reaction to a substance. Use this in everyday and clinical contexts such as food, pollen, or drug allergies.
  私のおいは卵たまごに対たいしてアレルギー体質たいしつだ。↗

  My nephew is allergic to eggs.
• 特異質とくいしつ
  nounPrimarily means idiosyncrasy, an unusual individual constitution or sensitivity, and only secondarily allergy. It is a less common word, seldom what you want for the ordinary medical sense of allergy.

For the medical sense of 'allergy' use 「アレルギー」; 特異質 is a less common word for idiosyncrasy and is seldom the word you want for allergy.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• アレルギーallergy
• 特異質とくいしつidiosyncrasy