# allergen vs allergy

> English confusable word pair

## The two words

### allergen
*noun · IPA /ˈælə(ɹ)ˌd͡ʒɛn/ · frequency rank #45,197*
A substance which causes an allergic reaction.

### allergy
*noun · IPA /ˈæl.əɹ.d͡ʒi/ · frequency rank #12,905*
A disorder of the immune system causing adverse reactions to substances (allergens) not harmful to most and marked by the body's production of histamines and associated with atopy, anaphylaxis, and asthma; any condition of hypersensitivity to a substance.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/allergen-vs-allergy