atopy vs immediate allergy

atopy and immediate allergy both are nouns.

Word	Noun	Adjective	Verb	Adverb
atopy	Yes	No	No	No
immediate allergy	Yes	No	No	No

As nouns, atopy and immediate allergy are synonyms defined as:

atopy and immediate allergy: an allergic reaction that becomes apparent in a sensitized person only minutes after contact

Other synonyms of atopy include atopic allergy, type I allergic reaction.

atopy (noun)	immediate allergy (noun)
an allergic reaction that becomes apparent in a sensitized person only minutes after contact	an allergic reaction that becomes apparent in a sensitized person only minutes after contact