Sounds to me that the EU lawmakers are a bit confused. I'll link a Wikipedia article about allergens.
https://en.wikipedia.org/wiki/Allergen
Interesting especially is the definition of antigen:
https://en.wikipedia.org/wiki/Antigen
Most allergens are actually protein based you could say.
In practice you could simplify it by saying that when you go away from something you are sensitive for, the reaction disappears rather fast. With an allergy the reaction can continue longer.
https://en.wikipedia.org/wiki/Allergen
Interesting especially is the definition of antigen:
https://en.wikipedia.org/wiki/Antigen
Most allergens are actually protein based you could say.
In practice you could simplify it by saying that when you go away from something you are sensitive for, the reaction disappears rather fast. With an allergy the reaction can continue longer.