Sun and Sand

Last week I was in Phuket for a few nights. And while elsewhere, people are celebrating the arrival of spring-summer, in these parts, there IS such a thing as too much sun.

I have terrible photo allergy, and so after being done to a crisp under the Thai sun, I’ve returned home with itchy hives all over my body.
I am having a tough time not reaching into my clothes to scratch myself vigorously while in public. It’s most annoying. Does anyone know of any home remedies?