Aquagenic urticaria is a rare condition in which a person’s skin develops red, itchy hives after exposure to water. There are about 50 cases of the condition reported in the medical literature. It was first reported in 1964. In aquagenic urticaria, hives appear on the skin, usually on the chest, abdomen, pelvis, back and/or arms after exposure to water. A form of physical urticaria, it most often affects women. The hives can last 30 minutes to 2 hours before going away. Treatments are available.
Can someone be allergic to water?
It may seem like a strange question, but the answer is “yes.” There is a very rare condition known as aquagenic urticaria (AU) where skin contact with water causes itchy, red hives or swelling. In severe cases, it can cause wheezing or shortness of breath.
There have been only about 50 cases reported in literature. The hives occur when the skin comes into contact with any type of water, including rain, snow, sweat and tears. The reaction is not impacted by the temperature of the water.
Symptoms normally start within 30 minutes of exposure to water and can last between 30 minutes and 2 hours. Symptoms usually go away on their own.
While aquagenic urticaria can happen in adults and children of any gender, it is more common in females during or after puberty.
Reactions do not typically occur when drinking water because the water doesn’t touch the skin. Some may experience symptoms on the lips or inside the mouth, however.
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What causes aquagenic urticaria?
The exact cause of aquagenic urticaria is unknown. There have been a few theories including: 3,4
- an allergen or chemical in the water (rather than the water itself)
- water interacting with something on the skin
How is aquagenic urticaria diagnosed?
Diagnosis of aquagenic urticaria is usually based on the reported symptoms by the patient. Confirmation may be done through a water challenge test. This test involves applying a cloth dampened with room temperature water to the skin for about 20 minutes.2 If the patient develops hives, the diagnosis is confirmed.
How is aquagenic urticaria treated?
With many things that cause hives, patients are told to avoid the trigger. But water avoidance is just not realistic. That would mean forgoing bathing, not going outside when it is raining, and avoiding activities that cause sweat. So treatment with medications is often needed.
Antihistamines are often recommended. Doctors prefer second generation H1 antihistamines because they cause less drowsiness. (First-generation medications may work as well but may have more side effects such as drowsiness.) Additional treatment is often needed.
Topical medications are effective in many cases. Creams can help form a barrier between the skin and water. Patients are advised to apply a petroleum-based cream or an oil-in-water emulsion prior to water exposure.2
If oral antihistamines and topical treatments are not effective, there are other options. Phototherapy has been used to treat aquagenic urticaria successfully in some patients. In addition, talk with your doctor about other possible treatments such as the biologic omalizumab, steroid medications, or selective serotonin reuptake inhibitors (SSRIs).2
How do you shower if you have aquagenic urticaria?
Treatment should make it easier for people with aquagenic urticaria to take a shower. Some people may need to limit taking a shower, however. People with aquagenic urticaria should speak with an allergist or dermatologist for guidance on taking a shower.
Neil MacIntyre, MD, is Clinical Chief of the Pulmonary/Critical Care Division, Medical Director or Respiratory Care Services, and Professor of Medicine at Duke University in Durham, North Carolina. He earned his medical degree from Cornell University in New York City in 1972.