I had GF at 12 & DD2 had it at 4. It does stay in your system coming back on you for years after, so its very possibly related. Neither DD or I had hives or a rash though.

But I have had DS in hospital as a baby & after his viral fevers & lethargy cleared up he did break out in a rash on his feet. I was told it was just the virus working its way through his system. Maybe this is similar? But that whole 'test' thing is really odd

Hope you did the Taylor Swift thing :P