There’s a VERY good chance it is, in fact, allergies…the question is whether this is environmental or related to food.
So, here’s an easy thing to rule out: what does your dog eat? If a dry kibble, what brand and formulation? Chances are you need to pick up a higher quality food with a novel protein. I would try something with zero corn or other grains and a protein source that *isn’t* chicken or beef. Ideally the food will have meat as the first three ingredients.
While you’re working on a food change, wash your dog’s paws every time she comes inside from the yard. Give them a good rinse with apple cider vinegar, too.
Finally: involve the vet. Depending on the severity of the reaction, your dog may very well need meds to get past this initial itchy spot.
I called my vet and was told that since she was only throwing up just give it a couple days. She was acting like my other cat did when she threw up worms so I got her drontal. She’s drinking a bit of water today and has been out more walking around the house but still not eating.