“Showers give me hives,” said a fifteen-year-old girl. She startled us with her complaint. Could she really have an allergy to water? Careful questioning revealed it had all begun with the sudden appearance of hives thirty minutes after waterskiing last summer. The hives were small mosquito bite-like bumps which appeared over her trunk and upper arms. Each hive had a distinctive red zone around it. They all gave a fierce itch, until fading away in an hour or two, leaving no trace.

Since that time, every bath and shower has been followed within minutes by these same small itchy hives. Indeed, swimming, sweating, or vigorous exercise did the same thing, although being under stress was not a trigger. She got relief by taking an antihistamine before bathing or showering.

We quickly proved the history was no hoax. Placing a wet towel on her upper back induced a fine crop of hives in that area within five minutes after it was removed.

But why? Was it something in the water? Was it the temperature? Distilled water, sea water, and salt solutions all elicited the same hives, whereas contact with alcohol or mineral oil produced no hives. In fact, coating the skin with oil prior to showering or adding bath oil to the bath reduced the severity of the attacks. Temperature played no role; hot as well as cold water produced the hives.

We could find no disease responsible, and extensive blood studies were negative.