I had to stop using the usual chemical-based sunscreens last year because I suddenly broke out in huge hives one day after putting it on and going in the sun. I read a lot and realized I had become allergic to them. You might actually be experiencing a chemical burn from the sunscreen combined with sun exposure!
Now i use ONLY non-chemical sun block- you know it from the fact that there are only two active ingredients: zinc oxide and titanium dioxide. I have no problems now, and they protect really quite well. Some of them can be a bit whitish colored but that works in and disappears if you apply evenly.