Can shower or bath water cause rashes?


Water urticaria, or aquagenic urticaria, is a rare condition in which hives develop within 1 to 15 minutes after contact with water. The hives last for 10 to 20 minutes and do not seem to be caused by histamine release like the other physical hives. Most investigators believe that this condition is actually exquisite skin sensitivity to additives in the water such as chlorine. The condition is sometimes described as “water allergy” which may not be accurate. Research seems to suggest that people with this condition are reacting to the substances in water such as chlorine and ions that are not distilled in water. A doctor can diagnose urticaria by exposing a patient to regular and distilled water and noting the reactions (the distilled water should not elicit a reaction). Once diagnosed, the patient can focus on the management of the condition. After proper management, some patients are able to build tolerance and become less sensitive to water over time thus allowing them to engage in more activities. It may be a good idea to carry a medical alert card on those diagnosed with urticaria so, in the event of an emergency, health care providers can be alert to their water sensitivity.

How do you know if you or a loved one has water urticaria? The diagnosis can be made by applying tap water and distilled water to the skin and observing the reaction. Water urticarial can be treated with a cream called capsaicin (Zostrix) that is applied to irritated skin. This is the same treatment used for shingles. Antihistamines, however, are not recommended since histamine is not the causative factor in water urticaria.


If you do not have urticaria and are noticing rashes on your skin, it may be from the chlorine in your shower. Tap water often contains at least as much if not more, chlorine than is recommended for use in swimming pools. More chlorine enters the body through inhalation while showering than through drinking tap water. Chemicals in showering water vaporize at a much faster rate than the actual water. This means the steam in a shower contains a higher concentration of chemicals than the water itself. If possible, try not to take such hot showers to reduce the number of chemicals in the air. The best solution would be to get a shower filter to remove chlorine or a whole house filter to remove the chlorine at the home’s entry point.

Other Causes of Rashes.

  • Heat rash. Heat can bring urticaria out, or make it worse.
  • Chronic 'idiopathic' urticaria. It is by far the most common form of urticaria, which lasts a long time. It has a puzzling name for a puzzling condition.
  • Cold Urticaria. If cold brings out your hives, take great care to avoid falling in the water, and see a specialist.
  • Pressure Urticaria. There are at least two completely different kinds of urticaria brought on by pressure on the skin.
  • Cholinergic urticaria. Tiny hives when you get hot. Sunlight can cause urticaria.
  • Solar urticaria. Hives caused only by direct sunlight, are a rather rare condition. The much more common 'polymorphous light eruption' can be mislabeled as solar urticaria.
  • Vasculitic urticaria, urticarial vasculitis.
  • Contact urticaria. Hives occur on the body from allergies to things touching the skin.

Urticaria caused by aspirin, and by food coloring and preservatives, and salicylates are easy to determine and should discontinue the use of these products immediately. The dietitian may make tablets unnecessary, but aspirin and some other painkillers could be dangerous. Urticaria is a very rare condition. However, if you or someone you know has it there are always ways to reduce the rashes by finding the right method to suit your lifestyle. Be patient and stay positive, don’t give up!

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