Have also suffered from the "sun allergy" during the last few SXM vacations. Always break out in itchy welts on the upper torso on about the 2nd or 3rd day. Tried switching to several different OTC sunscreens but no success. Dermatologist suggested doubling up on Claritin (antihistamine) during vacation last summer, but again no success. Dermatologist now suggesting I switch to zinc oxide based sunscreen like EltaMD. Will try this for upcoming SXM vacation in June.