That's not an allergy. Hazelnut coffee just plain stinks.
I can't stand flavored coffees, but hazelnut is the worst and stinkiest. Makes me gag and shudder. But if you got rid of my sense of smell for me, I could probably drink it just fine.
Even w/o a sense of smell, there's no way I could drink that swill! Because everyone knows I love coffee, you can just guess what I recieve alot of at Xmas. I finally had to be blunt.