So I think I have made a breakthrough. Now this obviously does not apply to everyone, since there are many reasons for hives and rashes, but for anyone struggling with hives that appear when they go in salt water or sweat, I think I may have figured something out. Now, I developed this strange allergy about 2 years ago. Whenever I went in the ocean, when the salt dried on my skin (particularly my face) I would break out in very itchy hives and immediately have to wash my face & body with fresh water & take an antihistimine to make them go away. This never happened in fresh water, like showers and pools, so I know its not aquagenic urticaria. The hives also started to occur on my face, chest & arms whenever I would sweat during exercise, or just on my face when I cried and the tears would dry. Since I worked in an allergy office with 3 great allergists I thought they would be able to help me with this issue, but none of them had any answer as to the cause & just suggested I take an antihistimine everyday & deal with it. This really depressed me, as I like to get to the root of problems, not just put a band-aid on them, so I started doing research on my own. The common denominator in all of these things would seem to be salt...but since it really isn't possible to be allergic to salt, since its a crucial part of our bodies, I knew it had to be something else. Now since the hives seemed to be the worst on my face, I started thinking that maybe I was putting something on my face (like a lotion, sunscreen or makeup) that was REACTING WITH THE SALT in the ocean, sweat and tears and causing my skin to irritate and break out in hives. Further research pointed to the fact that many people are allergic to the preservatives or fragrences or sulphates used in everyday products and don't necessarily realize it. Sometimes the allergic reactions happens immediately & sometimes it is a delayed reaction that is triggered by something else (like salt). Now these chemicals (parabens/fragrence/sulphates) are used in almost everything from moisturizers to sunscreens, to shampoo/conditioners, makeups, laundery detergents, soaps, etc etc etc. The problem is, if you are allergic to one of these things, you need to replace all of your products with hypoallergenic, paraben-free, fragrence-free natural products (which is a pretty big pain in the ass for women in particular since we use so many products). So I switched my face wash, moisturizer, makeup, body lotion, sunscreen, shampoo & conditioner, and laundery detergent to all oil-free, paraben-free, fragrence-free, sulphate-free products....and lo and behold...the hives stopped happening!!!!! So my advice to anyone with a problem similar to mine would be to see where the hives are happening worst on your body & think about what you have put on your skin recently, such a sunscreen, lotion, shampoo or even the laundery detergent in your clothes. I now have an appointment with a new allergist to have testing done for irritants in common household products, as I would like to know the specific chemical that I need to avoid. I will follow up in the future with the results. I hope this post will help some of you!