Allergic to Sun

I have insisted that I am allergic to the Sun.  I had a mild sun stroke today and I finally got some photographic evidence.

This is my inner arm.  I cannot find an explanation why I am getting rashes.  They are only in the inner arms, where is rarely exposed to UV.

It could not be food allergy, as I had not contained any protein other than gluten all day, and when my allergic reaction to lamb is rashes everywhere.  It would not be sun screen, as other sun screen areas did not have rashes.  It would not be allergens in the house, again, it is localised.  My mother speculated it could be the water in the thrill rides, but rashes areas did not include legs, as it would have been in contact with the splashes longest.

I resort to have a shower middle of the night to relieve my itches.  So I do have problem with the Sun!  (I am also glad to confirm other people could have the same problem.)