atopy vs atopic allergy

atopy and atopic allergy both are nouns.

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

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

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

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

atopy (noun)	atopic 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