Aquagenic Urticaria: An Overview of Rare Water Allergy

Aquagenic urticaria is a very rare condition where people have an allergy to water. Urticaria is a term that means hives or a rash. With aquagenic urticaria, people develop hives after exposure to water. This might include water from showers, sweat, swimming, or even tears.^1,2

What causes aquagenic urticaria?

We do not know what causes aquagenic urticaria. One theory is that an allergen or chemical in the water triggers the reaction. Another theory is that the water interacts with something already on the skin and causes a reaction.^1,2

With aquagenic urticaria, it does not matter what temperature the water is. This differs from other conditions where cold or hot water can cause hives. For some people, it does not matter what type of water it is. For other people, only salt water or only freshwater causes hives.^1,2

How rare is aquagenic urticaria?

Aquagenic urticaria is very rare. It is difficult to know exactly how common it is. But less than 100 cases total has been reported in research. Aquagenic urticaria is slightly more common in women.^2,3

What are the symptoms of aquagenic urticaria?

The most common symptom of aquagenic urticaria is hives after being exposed to water. The hives typically appear on the chest, stomach, pelvis, back, or arms. The hives show up very quickly after water contact – within 20 to 30 minutes. The hives may last between 30 minutes and 2 hours after contact with water stops.^1,2

The hives may be itchy and can also cause swelling. In some serious cases, aquagenic urticaria can cause wheezing, shortness of breath, and difficulty breathing. For some people, drinking water can cause hives in the mouth.^1,2

How is aquagenic urticaria diagnosed?

Doctors will often start the diagnosis process by collecting a medical history. You must explain things like when you got hives, what you were doing, and how long they lasted. They may try a challenge test if they think you have aquagenic urticaria.^1,2

A challenge test is a way to test for allergies by exposing you to a trigger in a safe environment. For a water challenge test, a doctor would place a wet cloth on your skin for about 20 minutes. The water will usually be at room temperature. If hives develop, it is a sign of aquagenic urticaria.^1,2

How do you shower with aquagenic urticaria?

With treatment, it should be possible to shower because treatment should manage symptoms. But, people with aquagenic urticaria may have to take less showers. A doctor or allergist should be able to give suggestions for showering with aquagenic urticaria.¹

How is aquagenic urticaria treated?

With many allergies, the recommendation is to avoid the trigger. But this is not practical with aquagenic urticaria. Water is an important part of our lives that cannot be completely avoided. So, aquagenic urticaria is typically treated with medicine.^1,2

Aquagenic urticaria can often be treated with oral antihistamines. Antihistamines are a common allergy medicine that are available over the counter. Oil-based or petroleum-based creams or lotions may help. If they are applied before water exposure, they may protect the skin.^1,2

Other types of drugs that may treat aquagenic urticaria include:^1,2

• Biologics
• Stanozolol (steroid)
• Phototherapy
• Selective serotonin reuptake inhibitors (SSRIs)

Not all treatments will work for everyone. So, it is important to work with your doctor to find a good fit for you.^1,2