Hi-Ya, Naysha!
We're so happy you've returned to the Disney Parks Moms Panel with another great question. Allergies can be scary, especially when you are traveling, but you'll be happy to know Disney really is the "Gold Standard" in assisting and providing for Guests with special dietary needs and requests.
There are several allergy-friendly snack options throughout the parks. Without knowing your specific allergy it's hard to recommend a few, but I can assure you there are options. Most snack stands have fresh fruit, hummus with vegetables and the like available and in late 2015 Disney released it's own line of allergy-friendly snacks called,
"Snacks with Character." These treats address many of the most common allergies including Gluten, nuts and dairy. Most of the single-serving options qualify as "snack credits" on the Disney Dining Plans.
If there is anything else we can assist you with, Naysha, please shoot us another question. Have a wonderful vacation and thank you again for stopping by.
Magical Wishes,
Lauren