The hives last for 10 to 120 minutes and do not seem to be caused by
histamine release like the other physical hives. Water urticaria is diagnosed by applying tap water
and distilled water to the skin and observing the reaction.
Treatment of water urticaria includes epinephrine, antihistamines, or cortisone-like drugs. Itching can be controlled with cold packs or commercial topical agents that contain menthol, camphor, eucalyptus oil, aloe, antihistamines, or cortisone preparations.