A 17-year-old girl from Utah has been diagnosed with a condition so rare there are only 50 other known cases of it in the world: she has severe allergic reactions to water.
Alexandra Allen, who is from Mapleton, was 12 the first time she experienced a painful rash and hives after swimming in a hotel pool while on a family vacation, reports ABC News. At the time, she and her family assumed she had a reaction to chlorine and she took Benadryl to reduce the discomfort.
But she quickly learned the chemicals in a pool weren't what caused the breakout after she experienced the same painful reaction after swimming in a lake that is known for being extremely clean. When Allen was 15, she self-diagnosed her condition after reading about aquagenic urticarial on a medical site. When she brought this information to her dermatologist, he agreed: the teen's body was unable to tolerate water.
"He brought in a few other doctors and they just sat around in awe," Allen told ABC News. She was tested to confirm the condition, and says she recalls having to soak in a bathtub and feeling like she was being "tortured."
Little is known about aquagenic urticarial, which isn't described as an "allergy," but as a condition that causes severe allergic reactions that can occur even when a person is exposed to rain, snow, sweat, or tears. It's more prevalent in girls than boys and reportedly begins around puberty.
Dr. Barney J. Kenet, a dermatologist with the Cornell Medical Center, says the cause of the condition is unknown, but that one theory is that the sweat glands within the skin produce a toxin that triggers the reaction. Another theory is that the antigens that cause the immune system to produce antibodies get absorbed in the skin after contact with water, which triggers the reaction.
In order to avoid causing a reaction, Allen says she has become a vegetarian to reduce the amount of oil in her skin, tries not to sweat, and only takes two to three very brief cold showers per week. The climate also poses a problem, as she recently learned while traveling to humid Cambodia with a humanitarian aid group.
Allen's condition is degenerative, which means it will get worse over time. At some point, she says, she may not be able to drink water.
Two women in the United Kingdom have been diagnosed with the same condition, reports the Daily Mail. One reportedly drinks Diet Coke because she can no longer drink water.