What is Water Urticaria (Aquagenic Urticaria)?
Water urticaria, also known as aquagenic urticaria (AU) or water allergy, is a rare medical condition in which hives develop rapidly on the skin as a result of contact with water (physical urticaria.)
Water urticaria may occur regardless of the source of water, it doesn't matter if the water is hot or cold, or if it has been chemically treated.
When Does Water Allergy Occur?
Since water urticaria may occur during any activity in which water comes in contact with your skin, this allergy can occur with
- bathing,
- swimming,
- or going out the side in rainy weather.
Aquagenic hives are thought to be a water allergy. However, research is limited.
According to a 2011 report, there are fewer than 100 cases of aquagenic urticaria reported in the medical literature.
Some patients with water urticaria experience a reaction if they come in contact with the water they drink.
In addition to external water sources, hives may occur in response to sweat and tears.
More women than men are affected by this condition which starts around the onset of puberty. Because the condition is so rare, there is no clear understanding of the cause or the effectiveness of treatment.
What is Physical Urticaria?
Water is only one of the physical factors that can lead to hives, and it's thought that six to 17 percent of hives classify as "physical urticaria." In addition to water, hives have been known to occur in response to cold, pressure, vibration, sunlight, exercise, changes in temperature, and heat. It appears that there is a distinct subtype of aquagenic urticaria in which hives only occur in response to salt water.
What causes aquagenic urticaria?
Researchers are still working to determine the exact cause of aquagenic urticaria. Some speculate it’s the chemical additives in the water, like chlorine, that cause the reaction, rather than contact with water itself.
The allergy-like symptoms you may experience from this rash are due to the release of histamine.
When you have an allergic reaction, your immune system releases histamines as a response to fight off the harmful substance. These histamines can trigger allergy-like symptoms depending on what part of the body is affected.
Symptoms of aquagenic urticaria Water Urticaria
The hives (urticaria) that are associated with water urticaria are rather small and usually develop on your neck, upper trunk and arms, but can appear anywhere on your body.
Similar to other forms of urticaria, symptoms of water urticaria include:
- Itching
- Burning sensation
- Elevated patches of skin (hives) - The hives are usually small, as noted, only 1 to 3 millimeters in diameter surrounded by a 1 to a 3-centimeter diameter of redness (the flare)
- Skin that has become flushed
- Sometimes the hives are combined with body-wide (systemic) symptoms such as wheezing or shortness of breath
In more severe cases, drinking water can cause you to experience symptoms including:
- rash around the mouth
- difficulty swallowing
- difficulty breathing
After exposure to a substance that contains water, symptoms should appear quickly (within 30 minutes). After your skin is no longer in contact with water, symptoms should subside within 30 to 60 minutes.
How is water urticaria diagnose?
Water urticaria is generally diagnosed by your family doctor or internist who will refer you to dermatologist or allergist to confirm your condition.
To diagnose aquagenic urticaria, your doctor will conduct a physical exam to observe your symptoms. They’ll also review your medical history, and may also perform a water challenge test.
During this test, your doctor will apply a water compress of 95°F (35°C) to your upper body. This is done to trigger a reaction. Symptoms should begin within 15 minutes.
Your doctor will record your reaction to the water challenge test and compare it to symptoms of aquagenic pruritus. Aquagenic pruritus causes itching and irritation but doesn’t cause hives or reddening.
Also, Your doctor will perform a careful exam and blood tests to rule out other conditions or diseases. Some people may develop hives for a number of different reasons which can; make the diagnosis more difficult.
What are the treatment options for Water Urticaria?
There’s no cure for aquagenic urticaria. However, there are treatment options available to alleviate symptoms.
Antihistamines are medications used to treat allergy-like symptoms. Your doctor may recommend you take a prescription antihistamine to calm your hives after coming into contact with water.
Medications - While first-generation antihistamines such as Vistaril (hydroxyzine) and Benadryl (diphenhydramine) may be helpful, they can be very sedating. The treatment of choice, therefore, is second-generation antihistamines such as Zyrtec (cetirizine) and Xyzal (levocetirizine) which are less likely to be sedating. That said, these medications alone are usually not effective enough to control all of the symptoms.
The medication Xolair (omalizumab) used for asthma has also been found to be effective for some people.
If you have a severe case of aquagenic urticaria and can’t breathe, you may need to use an EpiPen. EpiPens contain epinephrine, also known as adrenaline. They’re only used as an emergency alternative for severe allergic reactions. EpiPens increase blood pressure to reduce swelling and hives. They help the lungs function when they’re constructed.
Other treatments Water Urticaria -
There is evidence that using a petroleum-containing cream as a barrier between your skin and water may be effective when symptoms are not controlled by antihistamine therapy. Other treatments which have been tried include phototherapy, anabolic steroids, bathing in sodium bicarbonate solutions, and beta blockers.
You and your doctor will have to try various treatment plans to find the right one for you. In addition to the above treatments, there are currently clinical trials (medical research studies) in progress investigating newer and better treatments.
Support for People with Aquagenic Urticaria
There are support groups, Facebook groups, and a free national research registry dedicated to rare medical disorders. Many studies are looking for people with specific illnesses to help researchers come up with more effective treatments.
Preventing further flare-ups Water Urticaria
Once you receive a diagnosis of aquagenic urticaria from your doctor, you should try to avoid touching the water.
This isn’t always possible. Try to restrict your contact with water as much as you can. This includes taking brief, infrequent showers, wearing moisture-wicking clothes, and being mindful of the weather.
You may also want to change your diet to avoid foods that have high water content.
Sources:
Arikan-Ayyildiz, A., Isik, S., Caglayan-Sozmen, S., Karaman, O., and N. Uzuner. Cold, Cholinergic and Aquagenic Urticaria in Children: Presentation of Three Cases and Review of the Literature. Turkish Journal of Pediatrics. 2013. 55(1):94-8.
Gallo, R., Goncalo, M., Cinotti, E., Cecchi, F., and A. Parodi. Localized Salt-Dependent Aquagenic Urticaria: A Subtype of Aquagenic Urticaria?. Clinical and Experimental Dermatology. 2013. 38(7):754-7.
Rorie, A., and S. Gierer. A Case of Aquagenic Urticaria Successfully Treated with Omalizumab. Journal of Allergy and Clinical Immunology in Practice. 2016. 4(3):547-8.