By LOUISE CARR, Associate Editor and Featured Columnist
Pollen allergies, pet allergies, nickel allergies… we’ve heard them all. But an allergy to water?
It turns out this is definitely a thing. It’s called "aquagenic urticaria". And it can have devastating consequences.
An allergy to water means even the tears of your child or a kiss from your partner can make you break out in hives.
And taking a relaxing bath? Forget about it.
A water allergy is a rare and little-discussed health problem. It can cause redness, blisters, and itching – and simply taking a shower, a walk in the rain, or even a drink of water, can set it off.
While unusual, it is not surprising that you can be allergic to water. You can be allergic to practically anything. It turns out that a water allergy is one of the hardest allergies to deal with.
But How Is It Possible To Be Allergic to Water?
Since at least 60 percent of the human body is water, how is it possible for someone to be allergic to water and still survive? We’re all born from water in our mother’s womb, after all. Water is a basic human necessity – without it we die.
But let’s start with the basics. With a water allergy, the water inside the body is apparently not a problem.
It seems the allergic reaction is triggered by contact between the skin and water, and not having the water in the body or indeed, in many cases, drinking it.
Urticaria or hives can be triggered by a “wide variety of environmental stimuli, such as cold, pressure, vibration, sunlight, exercise, temperature changes, heat, and water” says a 2013 report from Dokuz Eylül University Faculty of Medicine in Turkey.
Indeed, “urticaria caused by physical factors has been reported as the cause of 6-17% of the chronic urticaria in children.”
Aquagenic urticaria, however, is particularly unusual.
How Rare Is a Water Allergy?
An allergy to water is extremely rare.
“Water induced urticaria is very unusual -- there are not many cases ever reported,” says Dr. Thomas Casale from Creighton University and the American Academy of Allergy, Asthma & Immunology.
Douglas L. Powell from the University of Utah Hospital has experienced only two cases of aquagenic urticaria in the past 15 years and he says that fewer than 100 cases of aquagenic urticaria have ever been written about in medical literature.
What Exactly Is Aquagenic Urticaria?
Aquagenic urticaria is indicated when hives develop after the skin is in contact with water.
It doesn’t seem to matter if the water is pure or dirty, or whether the water is cold or hot.
Water allergy is a type of physical urticaria and the Genetic and Rare Diseases Information Center from the National Institutes of Health says “due to the rarity of the condition, there is very limited data regarding the effectiveness of individual treatments; however, various medications and therapies have been used with variable success.”
Symptoms of a Water Allergy
A water allergy is demonstrated through symptoms similar to other skin contact allergies.
After contact with water, the exposed skin develops small red or skin-colored welts, commonly between 1 and 3 mm in diameter. This rash can occur anywhere on the body.
A 2011 study from The Catholic University of Korea in Seoul talks of a 19-year-old man and a four-year-old boy who suffered urticaria when taking a bath or shower, in the rain, or in the swimming pool.
Symptoms of the water allergy was “well-defined pin head to small pea-sized wheals … provoked by contact with water on the face, neck, and trunk, regardless of its temperature or source.”
It is itchy – in some cases intensely itchy – and can last anywhere between 30 minutes to several hours once the water source has been removed.
What Causes An Allergy to Water?
Given that so few people in the world have ever been documented as suffering from a water allergy, it is extremely difficult to identify trends and causes.
However, scientists believe that it is more common in women and some claim that it is caused by a hypersensitivity to minute levels of chemicals in water.
But this theory is difficult, as in many cases the water used to test for aquagenic urticaria is completely pure.
Research from experts such as Dice JP & Gonzalez-Reyes E in “Physical Urticarias”, March 2016 suggests that a water allergy is actually an immune response and not technically an allergy. The condition is caused by an immune reaction to something within the body – components within the skin release toxic materials when in contact with water, which leads to the immune reaction, which triggers the hives.
Some experts suggest that there may be an inherited link for a water allergy.
A 2009 study from Universidade Federal de Sao Paulo in Brazil reported a “case of familial aquagenic urticaria in Brazil (mother and daughter). Both patients presented wheals following contact with water, especially when showering, regardless of its temperature. The mother reported onset of urticaria four years before and the daughter presented wheals since birth.”
And in a 2002 study from The Free University of Berlin, Germany, aquagenic urticaria occurs over three generations in one family and is associated with lactose intolerance.
However, it is extremely rare for more than one person in the same family to be affected by the condition, which is probably why they attract attention in medical journals.
Salt Water Allergy Is a Problem for Some People
In some cases, it is specifically salt water that poses an allergic problem.
A 2015 study from Hôpital Civil in Strasbourg, France one case of aquagenic urticaria occurred solely on contact with seawater. The 32-year-old woman reported suffering hives several minutes after bathing in seawater. As a test, fresh water was applied to her skin but no reaction was seen in these locations.
In a 2013 report from the University of Genoa, Italy, there were “six young women who reported urticarial rashes, triggered mostly by sea bathing, characteristically localized on the inferior facial contours and neck. In four of the six patients, this was the only localization.”
Two women also reacted to tap water but less intensely.
Is There a Treatment for a Water Allergy?
As a water allergy is so rare, there is limited data as to which treatments work for the condition.
Several treatment strategies have been suggested by the Genetic and Rare Diseases Information Center at the National Institutes of Health, including, antihistamines; propranolol; ultraviolet B (UVB) light treatments (also called phototherapy); stanozolol (an anabolic steroid); barrier creams; a low dose of a selective serotonin reuptake inhibitor; and a bath with sodium bicarbonate.
A 1992 study from the University of Arkansas for Medical Sciences, Little Rock shows that one seven-year-old boy responded well to treatment with ultraviolet B and oral antihistamines.
A 2014 study from Robert Wood Johnson University Hospital, New Jersey demonstrates that an adolescent boy was successfully treated with “topical application of a petrolatum-containing cream as a protective coating.”
But unfortunately, in many cases the only treatment is complete avoidance of water on the skin, making a water allergy hard to live with.