Papular Urticaria or Chicken Pox?

I sold one of the boys' beds last weekend, so they are sleeping on their mattresses on the floor. Last Monday, Henry woke up with what I thought was a bug bite right at the base of his spine. As the day progressed, I noticed there were now three or four little bites there and quite a few around his neck line. So I washed all his bedding, vaccumed the floor, and didn't think about it again. Tuesday, he was the whiniest little guy ever. His tummy was pretty sad all day and just before bed, he had a little fever. Then the thought hit me- "What if he has chicken pox?" He got the vericella vaccine just over two years ago, but I've heard it could happen. Wednesday I called his pediatrician and in we went. Her words to me. "It could be chicken pox or it could be papular urticaria. I can't say for sure one way or the other." In English- It could be chicken pox or he could be having a super sensitive reaction to a bug bite. Um, thanks- that's what I said when I walked in the door. So she told us to treat it somewhat like chicken pox, but she wouldn't give us an official diagnosis of such. As the days have gone on, more spots have come and they all follow the traditional pattern, so I am taking a mother's liberty and diagnosing him myself. He has chicken pox! He was pretty sad to miss nursery today (we only went to church long enough for Hunter to give his very first talk in primary-which he rocked!) but other than that he's fine. The spots on his face are from playing in the mud Wednesday afternoon. He's a little ichy, but he's doing fine. There are more spots on his back, but these are the only pictures he'd let me take.