I immediately went online (what did we ever do before google??) and researched the symptoms, and since Paisley was still breathing okay (indicating her throat was hopefully not swelling, which is when this kind of thing gets really dangerous), we quickly got a Benedryl into her, wrapped in cheese. She didn't mind that one bit. We think that Benedryl may have saved our Lhasa Apso Columbus's life when he got into a yellow jacket's nest and received numerous stings when we were camping on property we used to own in the North Carolina mountains years ago -- far from any vet, cell phone signal, and also on a weekend. Fortunately, the Benedryl also helped Paisley significantly, and quickly. Within thirty minutes, I could see the swelling going down.
I sat with her on the sofa for another hour, watching her get calmer and calmer (at first she was frantically itching, drinking a lot of water, shaking her head, etc.), watching the swelling lessen, and when she was finally falling asleep, I put her in her crate. By this time it was 12:30 am, and with my adrenaline flowing from the episode, I couldn't fall asleep until at least 1 am, then got up a couple of times in the night to check on her.
Today she is much better. I gave her another Benedryl at 7 am, but even before that all the hives and redness were gone and most of the swelling. She's still got a "wattle" under her chin (a turkey neck, in keeping with the holiday weekend) where we can feel some swelling, and there's what looks like a small puncture wound on the lower side of her mouth, which is apparently where she got bit or stung. She's eating normally, playing like crazy, and seems to feel just like herself again, so we are out of the woods now, thankfully. As the day has gone on, the wattle is shrinking as well, so I suspect it will be mostly, if not all, gone by tomorrow. Note to self: ALWAYS keep Benedryl on hand.