What Is Aquagenic Urticaria?

Written by Sylvia Davis
Medically Reviewed by Zilpah Sheikh, MD on June 23, 2025
6 min read

Aquagenic urticaria is an extremely rare type of hives (raised, itchy rash) triggered by contact with water. Some people call aquagenic urticaria "water allergy."

Urticaria is the medical term for hives, which affect about one-fifth of the population at some point in their lives. But we only know of about 100 cases of aquagenic urticaria.

For those with this condition, the temperature and acidity or alkalinity of the water don't play any role in whether it causes a skin reaction. They may react to rain, snow, or their own sweat or tears. Some people with aquagenic urticaria may be able to tolerate the saltwater of the ocean, while others react only to saltwater.

Experts don't know a lot about what causes aquagenic urticaria. Scientists have put forward a couple of theories:

  • Some material that's dissolved in water passes through the skin and causes an allergic reaction. This substance, called an allergen, is what causes the hives — not the water itself. 

  • The reaction happens when water comes into contact with a substance on or in your skin.

Because the condition is rare, there's a lot we don't know about aquagenic urticaria. Doctors often have to treat hives without knowing what caused them. In chronic hives, they identify a cause in only about 10%-20% of cases. When they do know the cause, they may not understand the mechanism that triggers the rash.

Is aquagenic urticaria genetic​?

A family may have more than one case, but most cases don't happen in family groups. A few people with aquagenic urticaria disease have other inherited conditions. So far, there haven't been enough cases for researchers to determine whether the condition is inherited or part of a larger syndrome. 

There are no known risk factors for aquagenic urticaria. It often appears during puberty or young adulthood.

The rash you get with aquagenic urticaria appears as small, raised bumps surrounded by larger areas that may look flesh-color, red, purplish, or greyish, depending on your skin tone. The bumps may be itchy and sometimes painful. They can show up anywhere on your body but usually appear on your neck, upper arms, and trunk.

The rash often shows up 20-30 minutes after your skin comes into contact with water, though it can take several hours in some cases. It usually goes away in 30-60 minutes once water is no longer touching your skin. Sometimes, you develop other symptoms, including:

  • Headache
  • Shortness of breath
  • Wheezing
  • Dizziness
  • Fainting

Aquagenic urticaria rarely causes the serious allergic reaction called anaphylactic shock. This is a life-threatening reaction that can interfere with your breathing. It requires immediate medical treatment with epinephrine.

A doctor may suspect aquagenic urticaria if you have a history of rashes after water exposure. Still, heat, cold, pressure, and other conditions can trigger similar rashes. Part of the doctor's job is to get rid of those other causes of rash.

Doctors usually diagnose aquagenic urticaria using a "water challenge test." Your doctor places a room-temperature wet compress on your chest, then checks for a rash after 20 minutes. They usually do this test on the upper half of your body since symptoms are more common in this region.

It's important that you don't have any antihistamines in your system during this test. Also, the water used in the challengeshould be neither hot nor cold.

There's no cure for aquagenic urticaria. The only way to prevent symptoms is to avoid water, but this isn’t a practical solution. Instead, your doctor will suggest aquagenic urticaria treatment to help you deal better with being exposed to water.

Those with the condition commonly use two strategies to manage it: 

Antihistamines. The usual treatment for hives, no matter what type, is antihistamines you take by mouth. Doctors prefer the type called second-generation antihistamines because they cause less drowsiness than the older formulas. Cetirizine is a frequent choice.

Topical medications. These are petroleum- and oil-based creams you apply to your skin. These form a barrier that protects your skin from water. Some experts recommend trying them before antihistamines, especially for children who are allergic to water.

If those treatments aren't effective, your doctor might recommend other options, such as:

Ultraviolet light therapy. Phototherapy using ultraviolet light is a less common treatment. It toughens the skin and makes it less sensitive to water. The idea is to make the skin more like that on the palms of the hands and the soles of the feet, as water rarely causes a reaction in those places.‌

Omalizumab. Doctors have had some success treating hives with the biologic allergy medicine omalizumab (Xolair). One person with aquagenic urticaria got rid of all symptoms and could even go swimming after using this drug. But omalizumab is only prescribed off-label for hives because it's not FDA-approved for this purpose. It's also more expensive than other treatments.

Corticosteroids. Steroids such as prednisolone or prednisone may help ease hives by reducing inflammation.

Selective serotonin reuptake inhibitors (SSRIs). Though they're usually used to treat depression, these drugs are also thought to have anti-inflammatory effects.

Talk to an allergist or dermatologist about your treatment options. Allergists, also called immunologists, specialize in treating allergies. Dermatologists diagnose and treat conditions of the skin, hair, and nails.

It's important to know exactly which situations trigger your symptoms. And always keep antihistamines on hand so you can treat symptoms quickly when they arise.

Here are some ways to manage:

Drinking water. Most people with aquagenic urticaria can safely drink water as long as it doesn't touch their skin. But it's possible to have a reaction when the water comes into contact with your lips or the inside of your mouth. Using a straw might help.

‌Bathing. Treatment can make bathing and showering less risky. Petroleum- or oil-based creams can help protect your skin. Often, people with aquagenic urticaria bathe less often. They may use wipes, alcohol-based cleaners, and dry shampoos instead. 

Other exposure to water. People with aquagenic urticaria often take precautions such as staying inside or wearing protective clothes on rainy days. Rubber gloves can help protect their hands during household chores. They may also try to avoid becoming overheated and stay away from activities that cause sweating.

How do people deal with aquagenic urticaria?

Being allergic to water presents some challenges in everyday life. If you're struggling, connect with local or online support or advocacy groups. These groups can help connect you with others who have the same condition. They can also guide you toward further research and helpful resources.

With aquagenic urticaria, sometimes called water allergy, you break out in hives when your skin touches water. While there's no cure, treatment can minimize the challenges of dealing with this very rare condition. With the right treatment and some lifestyle changes, most people with this condition are able to maintain a good quality of life.

 

Can you shower if you have aquagenic urticaria?

Some treatment options — especially topical creams that protect your skin from water — can make it easier to take a shower. But they may not be effective for some people. You may have to cut down on how long or how often you shower. 

What is the life expectancy for aquagenic urticaria?

Aquagenic urticaria is not a life-threatening condition, though the symptoms can be uncomfortable. It doesn't seem to affect lifespan.

Can aquagenic urticaria water allergy be cured?

There's no cure for aquagenic urticaria. But treatment can help you manage your symptoms. It doesn't usually get worse over time, and symptoms sometimes improve on their own.