I'm allergic to ice cream...?

Okay. It seems as though I'm having a hard time accepting the fact that I'm allergic to ice cream. I mean who doesn't love ice cream?! However, in the past two months I've realized that I've become allergic. Symptoms include swollen lips, and itchness. At first I was in denial and continued eating it. Then I realized that it's starting to affect my breathing. So I obviously realized that it was not worth it. I just don't understand the random onset of the allergy? I mean I've eaten ice cream ALL my life and it was fine, until as of recently? It's not the brand - I've tried several brand to test that theory and the same thing happened. So what am I allergic to? (I'm pretty sure I'm not lactose intolerant as well).