Are you talking about skin allergies or respiratory?
Over the years, I have developed sensitivites (and most likely allergies) to most products out there that are applied to the skin. Sometimes the "organic" or "natural" ones are the worst. I get hives and welts. Basically, I cannot use any special creams, potions, or lotions. There are probably some safe ones out there, but I'm tired of spending money trying to find out.
I wash with either Dove White or Dove Sensitive skin bar and I moisuturize with straight Vaseline. Keeps me totally non-irritated. My DD is somewhat sensitive and she's had VERY good luck with The Body Shop's Sensitive Skin line so I may be giving that a try (best of all, you can buy a sampler package). Her friends have used it when they've stayed over and they all say the same thing--their skin is no longer red and it feels so good.
Now, if you're talking respiratory--I can no longer be around most perfumes are candles, although I'm fine with some.