Itchy Itchy

I wanted to see if anyone knew what this rash/allergic reaction/redness is on my neck, arm, and hand? It just recently popped up, but the strange part is the way it starts to itch as soon as I get into my car every evening. It started up two days ago. I feel an itch on my back and then it works it's way to my neck and then down my arms. Last night it stayed on my right arm until about 8:30; itching and itching and itching. My right hand and fingers got all swollen and so did my arm. It was getting pretty bad and Neal hadn't gotten home yet. I was really freaking out. He thought it was heat rash, but I've never had heat rash before plus my car isn't that hot by the time I get off work so that doesn't make since. And with heat rash how long does it last? I was out of the heat for the longest time. I sat in my car with cool air on me taking pics and sending them to Neal as the pain got worse and worse. I really don't know what it is. Maybe someone else will know.Take a look at the pics please and let me know what you think it could possibly be.

It started with my back and then my neck....





My right arm itched soooo bad!





Neal thought it was a phantom itch at first. HA!



My hand swelled up after this. My fingers my hand; Awful!
We still dont know what is causing it. I guess we'll see if it happens again tonight. Let me know what you think it could be? Thank you.

xo,
Kim