It is possible to be allergic to water, according to the U.S. National Library of Medicine. Walter B Shelley and Howard M Rawnsley first described the condition, known as aquagenic urticaria, in medical literature in 1964. Since that time, there have been less than 100 cases reported.
Urticaria is a condition where the skin forms lesions, known as wheals, upon contact with chemicals or other conditions, according to WebMD. The Journal of Allergy and Clinical Immunology: In Practice describes a woman with an allergy to water. Placing a test tube filled with hot water or a dry bag of ice against her skin for five minutes caused no reaction. However, a room-temperature wet compress left in place for 16 minutes before removal caused the formation of a rash.