What Causes Itchy Small Red Bumps On Lower Legs?

I returned from Puerto Rico on Monday and I thought I had a bunch of bug bites, but it appears as though I have more bites now than I did when I returned. They are small red bumps that are extremely itchy. They appear in large groups on my lower legs and elbows with a few random bumps on my upper legs and arms. I ve had chicken pox when I was a child so I m assuming it s not that. Any suggestions? I had also thought it could be bed bugs, but my wife doesn t have any.