beach and swimming

When water is your enemy | Day 161

In Australia, frolicking through bodies of water in order to lower your core temperature is a national pastime, particularly in summer. And most people don’t have to think twice before going to the beach for a swim, or jumping into the pool at a friend’s place.

Water is essential to most living things, and the human organism is no exception, with its water content estimated between 55 and 78 per cent. But what if you had a reaction to this most basic of substances, and simply couldn’t bear skin contact with it?

My boyfriend knows exactly what that’s like. Since teenage years he has been experiencing an extremely rare skin condition called aquagenic pruritus (Latin for “water-induced itching”). It means that every time after direct contact with water – showering, bathing, swimming – his skin starts to itch with a thousand pin-pricks, and no amount of scratching can alleviate it; he just needs to wait until it fades away some 20-30 minutes later.

This happens every morning after he’s had a shower, no matter how swift. Every time after a swim. Itching. He doesn’t take baths, because it’s simply not worth the severe discomfort afterwards. There are no visual symptoms, no rash, welts, or swelling, so many people around him find it difficult to understand – this reaction is happening.

Aquagenic pruritus is so rare that until the 1980s it was hardly described in the medical literature. My boyfriend was diagnosed with it as a “water allergy” in the late eighties and prescribed antihistamines, which didn’t really help and just made him drowsy all the time.

Even today the mechanism for what triggers this skin reaction is not entirely clear, because it is not an allergy  in the typical sense, as in caused by excess histamine. Instead, the culprit seems to be buried somewhere between a misfire in the sympathetic nervous system and a problematic response to some neurotransmitters.

The research on aquagenic pruritus is still thin on the ground, and only a handful of studies have examined particular cases or attempted some treatments with varying luck. Overall the results on treatments are contradictory, and all the individual studies are so small and far apart, that nobody has even bothered to do a meta-review to try and conclude something useful from it all.

Usually, when faced with a medical problem and in need of a cure, one can go to a healthcare specialist who will have knowledge of the scientific literature. They will be aware of the consensus of what the best treatment is, and be able to provide you with it. But this is not the case when you enter the land of extremely rare conditions, because there simply isn’t enough data to draw a reliable conclusion on what’s causing it and say “here, take this and it will be all better.”

So you have to experiment with what you’ve got and perform DIY science at home. I stumbled upon a very small study from 1994 in which five people were treated with capsaicin cream, and all five were symptom-free by the end of the four-week course. The researchers thus theorised that substance P, which is the neurotransmitter that reacts to capsaicin, is involved in causing aquagenic pruritus.

Because all the other potential treatments, such as ultraviolet phototherapy, taking anti-depressants or neuroleptics are more invasive and expensive, we have decided to try capsaicin cream in a home experiment. Yes, this means my boyfriend now has a designated test area on his chest where capsaicin cream will be applied three times daily for four weeks. The sensations there will be compared to control areas which did not receive capsaicin, such as legs. It’s a primitive study design and it’s not even blinded, but at least we can avoid accidentally taking regression to the mean for a positive result.

I’ll report back.

Do you know anyone with aquagenic pruritus?

Update: Here’s what happened with the whole capsaicin test.

11 thoughts on “When water is your enemy | Day 161”

  1. I have had AP since about 1988, and I am now moderator of a Yahoogroup which includes over 1000 people who have this problem. If he’s not already in the group, your boyfriend can join by sending an email to aquagenicskin-subscribe@yahoogroups.com. We share our individual solutions, which gives others ideas about what they might try. Believe me, some people would say that capsaicin is MUCH more invasive than narrow-band UVB treatments. Some refuse to use it because it was too painful when they tried it. I found the capsaicin very helpful until I developed a sensitivity to it. After regularly coughing and sneezing every time I pulled my pants down (thus exposing my legs, on which I had put the capsaicin) I decided it wasn’t worth it. Showering only at night and ending with the hottest water possible, wearing only 100% natural fibers, plus getting UVB treatments 2 or 3 times a week, has given my life back to me!

    Is is trying the capsaicin on his chest because that’s where he itches? If so, that’s unusual. Most of us itch most on our arms and legs. I would do the test on the places that itch the most! When I was testing things like that, I would treat one leg and not the other, which provides a more comparable control.

    In any case, good luck! My spouse knows that the AP can negatively affect the life of partners, too, even if you don’t feel the itch!

    1. Thanks for such a nice comment, Marnie! Without TMI, yes the areas involved are chest, arms, and legs. We did deliberate over control areas a fair bit, both being scientifically minded and wanting the most reliable results.

      So far capsaicin has not been painful at all.

      I will report back on my blog here once we see the results of the experiment!

      1. Gosh, if the capsaicin hasn’t been painful, maybe he’s not using enough! ;-)

        I used to love the glow from the capsaicin, which was “louder” than the itch — at least, that’s how I described the reason it worked.

        1. I don’t know, it is somewhat odd that there is hardly any burning. He eats so much hot food that perhaps he’s ran out of substance P, haha! (No. That’s not how it works, of course.)

  2. P.S. I found this story on your blog by having a Google alert on “aquagenic pruritus”. For this, I celebrate Google, which has its home office not far from where I live.

  3. Hi I’ve made a doctors appointment because I’m positive I have the same thing! I am 30 and have had itching after a shower, swim etc on arms and legs (mostly) since I was 11 or 12 years old. No matter with soaps or without! It is much worse in the mornings, nights are better (in shower) but if humid or shave my legs, the itching starts bad. If I have a shower in the mornings I end up in the fetus position under my blankets scratching until around 20 minutes it subsides and if I shave then I feel like I want to rip my skin off! No rashes or marks on skin other then from me scratching!

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  5. I have had this problem since I can remember. I remember being a little girl screaming after I showered because i was so itchy. My mother used to tell me that it was “all in my head and to stop crying”. I am 46 now and i have chosen to live my life single because no one understands what I am going through. I have been to my family doctor about this problem and she like most other people think that I dry skin or that it’s “all in my head” she has prescribed me skin creams that don’t work and sent me to allergists that never found anything I have tried antihistamines and they never helped. I even had one doctor tell me that I’ve been living with it this long and that it’s only something that bothers me for a hours or so a day so I might as well continue living with it. It’s been very frustrating and I have learned to live with it. I just found this post this morning and I must say it’s nice to know that there are other people in the world that are experiencing the same thing that i am experiencing and it’s nice to know that this problem is not “all in my head”. If anyone knows of a specialist that I can talk to in Toronto who can help me instead of just scratch their head and shrug it off and send my on my way, I’d really appreciate it!
    Thanks for the support!!

  6. Christine,

    Not many people read comments here, as compared to our aquagenicskin yahoogroup, which has over 1300 members.

    If you join the group and post your question there, not only might you get an answer about doctors in your area, you might also learn some helpful strategies from others!

    To join, send an email to aquagenicskin-subscribe@yahoogroups.com

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