Can people be allergic to water? Scientists say this rare condition makes it possible
For most people, water is harmless, even comfortable. It cools the body on hot days, washes away dirt and makes up about 60 per cent of the human body itself. But for a small number of people around the world, contact with water can cause painful, itchy hives within minutes.
The condition known as aquagenic urticaria is so rare that only a limited number of cases have been formally documented in the medical literature.
Researchers say patients may react to rain, showers, swimming pools and, in some cases, even their own sweat.
Although scientists still do not fully understand this disorder, decades of medical studies confirm that this rare condition is real.
What do scientists know about water allergies?
In 1964, researchers F. Shelley and W. Rawnsley first described this condition, documenting patients who developed hives after exposure to water. Since then, dermatologists and immunologists have been trying to understand why this happens.
Scientists believe that people are not actually allergic to water itself. Instead, water can interact with substances in the outer layer of the skin, causing immune cells called mast cells to release histamine, the chemical responsible for itching and inflammation.
A 1981 study by researcher RG Sibbald and colleagues found evidence of histamine release during exposure to water, lending support to the theory that the condition is associated with an abnormal immune response rather than simple skin irritation.
Symptoms may appear within minutes
People suffering from aquagenic hives usually develop small raised lesions and intense itching soon after water touches the skin. The reaction usually appears within 20 to 30 minutes and may last for an hour or more.
The longer the exposure, the more severe the symptoms may become. Doctors say that even routine activities can become difficult.
If sweating causes a flare-up, patients may need to take shorter baths, avoid swimming, or limit exercise. Interestingly, most people with this condition can still drink water normally because the reaction occurs through skin contact rather than through the digestive tract.
Because the disorder is so rare, diagnosis can take time. Doctors often rule out more common causes of hives before considering aquagenic hives.
The standard diagnostic method is called a water provocation test, where a cloth soaked in room temperature water is placed on the skin for about 20 minutes to see if hives develop. Researchers Robert Rothbaum and Gene S.
Medical reviews, including McGee’s 2016 analysis, have highlighted how difficult the condition can be to recognise, as many physicians may never encounter a case during their careers.
Is there any treatment?
There is currently no cure for aquagenic hives, but treatment can help control symptoms.
Doctors usually prescribe antihistamines, which block the release of histamine in the body. Some patients with severe symptoms have also responded to therapies such as omalizumab, a drug commonly used for asthma and chronic allergic conditions.
A 2022 systematic review by researcher Chuda Rujitharanawong and colleagues found that antihistamines remain the primary treatment option, although researchers are still searching for more effective treatments.
A mystery scientists still can’t fully explain
Despite decades of study, scientists still don’t know exactly why some people develop aquagenic hives. Researchers are investigating whether a substance secreted in the skin activates the immune system by reacting with water.
For now, the condition remains one of medicine’s strangest documented disorders, a rare example of how the body can sometimes react to even the most essential substance for life.
