> <i>Experts say to minimize ivy's reactions, they need to purify the water systems and use central air so she doesn't overheat.</i><p>So she is allergic to something that is dissolved in tap water and other usual presentations of water. (Is she allergic to bottled water? All the brands?) Not allergic to H2O. Almost all the foods have a 30% or more part of H2O, so being allergic to H2O is ultra fatal.