What Is Aquagenic Pruritus?

Imagine having a condition that causes intense itching when your skin is exposed to something that is literally unavoidable. And by unavoidable, I mean your body even makes it itself. That's the case for Niah Selway, a young woman from the United Kingdom.

Selway, who has over 150,000 subscribers on YouTube, can't sweat, cry, or take a shower without experiencing debilitating pain. The condition is called aquagenic pruritus, and according to the Genetic and Rare Diseases Information Center (GARD), it causes intense itching when the skin comes into contact with water of any temperature.

It's important to note that aquagenic pruritus is not an allergy to water. An allergy would involve an immune hypersensitivity reaction in the body, which can sometimes be severe. But aquagenic is different. It is a skin reaction and is not life-threatening.

Thankfully, Selway's internal organs aren't affected, so she can still drink water. Selway posts videos about her condition on her YouTube channel. Selway explained that she would have occasional reactions as a child, but doctors couldn't figure out what she was allergic to (if anything).

As Selway got older, the reactions became more frequent, and she was eventually diagnosed with aquagenic pruritus ("aquagenic" means caused by water and "pruritus" means itching, so aquagenic pruritus literally means itching caused by water).

What Does the Science Say About Aquagenic Pruritus?

According to the GARD, aquagenic pruritus has no known cause, though it can run in families. It may be a symptom of an underlying condition, such as blood cancer, though it's not clear if this is the case for Selway.

Beyond the GARD, it's extremely difficult to find much information on aquagenic pruritus. Interestingly, while the National Institutes of Health (NIH) qualifies aquagenic pruritus as a rare disease, a 2017 review study published in the Central African Journal of Public Health states that aquagenic pruritus is common in certain parts of the world, including tropical countries like Nigeria.

This study also describes possible causes that could be related to the development of the disease. At the top of the list is over-reactive mast cells. These cells produce histamine, the substance your body produces when it comes into contact with something it's allergic to. Histamine is also produced at the site of an injury (think swollen sprained ankle).

The other possible underlying causes of aquagenic pruritus include other various chemicals in your body over-reacting, and the sympathetic nervous system not behaving the way it's supposed to. Of note: This study also refers to previous research that found that lactose intolerance may play a role. For about 25% of individuals with aquagenic pruritis, lactose intolerance may be a contributing factor.

This same 2017 review describes the pain as burning, stinging, and prick-like. The researchers list several therapeutic agents that have been used with some success in people with aquagenic pruritus. They include antihistamines, phototherapy, capsaicin cream, baking soda baths, and even heart medications called beta-blockers, which are often given for high blood pressure and abnormal heart rhythms.

Selway explains on her YouTube channel that she's tried several treatments, and none have worked. And while her doctors told her there isn't a cure, Selway is hopeful she'll outgrow the condition.

How Do You Avoid Water?

It's nearly impossible to completely avoid water. Even your pee is made with it.

"I cannot go for a wee without having an allergic reaction," Selway said in one of her videos. "I have an allergic reaction all over the back of my thighs and my bum and it travels all the way up my back almost every single time that I go to the toilet, so that is at least four times a day, and that's on a good day."

Selway also has to avoid the rain, which makes it difficult for her to leave her home on a rainy day. "Whether I take an umbrella or not, whether I take an all-in-one waterproof wetsuit, there is absolutely no way for me to step outside the house when it's pouring with rain and not get a single drop of water on my skin because that's all it takes."

Selway said her reactions can last for up to three hours. Selway even made a YouTube video of herself taking a bath to show her subscribers what it's like to have an allergic reaction to water.

"It's about adjusting, and it's about staying strong," Selway said, "and it's about using this horrible, horrible experience and this immense challenge to make myself a stronger person and to use it as something to make me grow."

What Selway is doing is bravely giving others a glimpse into what having a rare condition is like and encouraging them to (hopefully) be more compassionate to those who have conditions that aren't understood.