Recurring rash

I took my DD to the GP a few weeks ago because she had a rash on her arms, legs and face. It was Ted, blotchy and slightly raised. The GP said it was a contact rash and put it down to the sunscreen I'd used on her the day before.

A few days later she got a rash on her belly. I took her back to the GP when it didn't go after a day or so and she developed a cold at the same time. We saw a different GP that time, and she said she thought the cold was a coincidence, and that the other GP was wrong and the rash was a contageous virus and should go after 5 days.

The rash went, and the cold went too a couple of days later. Now, a week after the rash disappeared it's back on her belly. The GP described it as lacy, it's pale pink tiny dots in clusters. It came up yesterday, looked a bit better this morning but worse again tonight.

I'm hesitant to go back to the GP yet again, starting to feel like a hyperchondriac and besides they clearly seem to be guessing at what it is. I'm starting to wonder if it could be a food allergy... She sometimes gets little red dots around her mouth too, but I always assumed that was due to dribble.

Does this sound familiar to anyone? Any ideas what it could be?