Is it okay to take a shower when you have urticaria?

Yes: Urticaria or hives are superficial lesions that are red, itchy and can wax and wane. There is no reason not to take a shower. In fact a tepid shower or bath may relieve the itching a little in addition to antihistamines. For some who have cholinergic urticaria (heat induced) a hot shower could make it worse.

Yes but:): An exceptionally hot shower can stop the itching temporarily, but if it's long enough and hot enough it can drop your blood pressure enough to cause you to faint while in the shower. I would avoid it.

No hot showers: Urticartia, in most cases is the result of oozing fluid from blood vessels. If you take a hot shower, you dilate the blood vessels and you will make the welts worse. A cold shower may temporarily reduce the size or resolve the urticaria temporarily. If not tolerated, use lukewarm water. Along with the showers, take an antihistamine such as fexofenadine or cetirizine.