I suffer from the water filled blister type and so now go to my GP a couple of weeks before I go away for horse strength anti histamines which I start to take a week before I go
Simple do a fantastic sun cream range which doesn't block pores and has some sort of anti allergy stuff in it - better than the Piz Buin in my experience. I've only ever seen it on sale in Boots - best still though it's usually on buy one get one free and a little bit goes much further than any suncream I've used
I wouldn't risk having an injection over in
Icmeler in case it made my sun allergy worse, tempting though it is