Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff,
Speaker 1: Lauren bug Bomb here. When Alexandra Allen was twelve years old,
Speaker 1: she did what most kids do when they're on a
Speaker 1: family vacation. She went for a swim in the hotel pool.
Speaker 1: Unlike most kids, though, Alexandra had a severe reaction to
Speaker 1: her swim. Her skin broke out and angry, itchy welts
Speaker 1: just a few short hours after leaving the water. What
Speaker 1: began as an ordinary summer day ended in the eventual
Speaker 1: diagnosis that would change Allan's life. She shelved her dreams
Speaker 1: of living on a sailboat and working as a marine
Speaker 1: biologist after discovering she was allergic to water. An allergy
Speaker 1: to water seems like an improbable condition. After all, water
Speaker 1: is a chief chemical component in the human body, accounting
Speaker 1: for at least six of the average person's weight. Water
Speaker 1: whisks toxins out of critical organs, fairies nutrients to hungry cells,
Speaker 1: and creates the human conditions needed for ear nose, and
Speaker 1: throat health. In short, water is essential to life. In
Speaker 1: the case of water are allergies, only the skin is affected.
Speaker 1: People with this condition can still safely drink water. It's
Speaker 1: only when water of any temperature or origin touches the
Speaker 1: skin that a hypersensitive allergic reaction occurs. The condition, known
Speaker 1: as aquagenic uticaria, is called an allergy, but isn't medically
Speaker 1: classified as a true allergy. It's actually an allergy like
Speaker 1: reaction that belongs to a subset of physical r tucaria,
Speaker 1: a group of conditions characterized by hives or welts that
Speaker 1: arise from stimulation of the skin. In the case of
Speaker 1: aquagenic ur tcaria, red swollen, itchy bumps form when water
Speaker 1: touches the skin. This histamine reaction isn't directed at the
Speaker 1: water itself, but is most likely a reaction to a
Speaker 1: water soluble antigen that stimulates antibodies. Any type of water, distilled,
Speaker 1: tap or rain will cause an outbreak almost immediately, and
Speaker 1: can make bathing or getting caught outside in a rainstorm
Speaker 1: a tortuous proposition. Aquagenic Uricaria is so rare that fewer
Speaker 1: than one occurrences have been recorded in medical literature since
Speaker 1: the first cases were described in nineteen sixty four. It
Speaker 1: affects women more than men, and most often begins during puberty.
Speaker 1: It's usually diagnosed by putting the skin into prolonged contact
Speaker 1: with water. In Alan's case, physicians asked her to soak
Speaker 1: in a tub to diagnose the condition. The cause of
Speaker 1: these water allergies still eludes experts. One theory is that
Speaker 1: sweat glands could be the culprit. It's possible that sweat
Speaker 1: glands in certain people produce a toxin that leads to
Speaker 1: an allergic reaction with water. While researchers remain on shore
Speaker 1: of the root cause of the condition. Most cases can
Speaker 1: be treated with antihistamines and controlled by avoiding contact with
Speaker 1: water as much as possible. Today's episode was written by
Speaker 1: Laurie L. Dove and produced by Tristan McNeil. For more
Speaker 1: on this and lots of other weird topics, visit our
Speaker 1: home planet, how Stuff Works dot com.