Hello, everybody...
My mother has had a skin condition for years and years - she is allergic to many topical cosmetics/all sunscreens (besides some antibiotics, and being lactose intolerant, etc.). The doctors put her through tests and they thought that she was allergic to PABA, but when they put her on PABA-free sunscreen, she still broke out. She breaks out seriously - once, when the response was to trying on clothes in a department store (she thinks), she had a large, painful rash covering probably 1/3 of her body for many months (six?). What was interesting this time, though, was that she tried a new sunscreen by rubbing a decent amount on her arm and waiting a week, and she didn't break out at all - but when she used the same bottle of sunscreen in Cuba, she had a horrible reaction (had to get injections, go on medication - her legs are swollen considerably, and red, and she has large blisters, limps when she walks). The only difference in application was that, in Cuba, she actually was wearing it out in the sun, it wasn't just being worn inside. Could it be possible that she's allergic to a byproduct produced when sunscreen is exposed to sunlight, or something?
Thank you!