It’s hard to imagine a life without water. No bathing. No going outside in the rain. No swimming. Crying, and sometimes even sweating, is an unfortunate incident. People with the incredibly rare (though, one allergist suggests, wildly under-diagnosed) water allergy, aquagenic urticaria, have painful headaches and red welts when they come into contact with water. But how, you might ask, can a human even survive with this condition? After all, our bodies are over half water. Well, the vast majority of sufferers only have problems when their skin touches water — so they can drink all they like, and their own body isn’t hazardous to them.