You can be allergic to water

Think you have it tough? At least when you're feeling miserable you can cry. Some people break out in hives when they cry, because they're allergic to the water in their own tears.

On stressful days, I enjoy going for walks in the rain. Either they cheer me up, or I can tuck away my umbrella and pretend I'm Eponine in Les Miserables, and that cheers me up. Nut even that basic comfort is denied people who suffer from aquageic urticaria. Also known as aquagenic pruritis — water itch — it's an allergy to water. Some comparatively lucky souls only run into trouble when the water is cold, but for many it's any type of water at all.

This sounds like a condition that should kill a person. We all need water to live, after all. It seems, though, that the allergic reaction doesn't kick in when they drink water or in reaction to the water in their cells, but only when water is applied to the skin. This topical exposure includes a person's own tears, sweat, or saliva — any external liquid that's mostly water sets the reaction off.

Minor allergies result in itchy hives that last for only a few minutes, but more unlucky sufferers get bright red, aching rashes and blinding headaches after only a minute's exposure to water. They bathe as little as possible and try to limit their time in conditions that might make them sweat. One woman with aquagenic urticaria drinks mostly Diet Coke, because it's easiest on her lips and skin.

No one is exactly sure why people develop an allergy to water. Sometimes there's a triggering event, like the onset of an illness, but other times people simply begin to notice themselves breaking out in hives every time they wash. They assume it's a reaction to the soap, until some doctor breaks the bad news. Doctors know that when water hits the skin of a person with this condition it triggers the release of histamines — present in most allergic reactions — and acetylcholine.

Acetylcholine is a neurotransmitter that modulates the body's autonomic nervous system. The autonomic nervous system controls stress reactions, and is in charge of, among other things, the muscles that regulate muscles under the skin that make body hair stand up and control the expansion of blood vessels. How water, of all things, triggers the allergy, isn't known.

There are treatments, including antihistamines, that can suppress symptoms. Occasionally water allergies disappear after a few years. In the meantime, most patients have a lot of miserable rainy days.

Top Image: Matthew Bowden

[Via MSN, NBC]