In early December, about a week and a half into my nutritional ketosis experiment I started to develop a rash on my body. It began in my abdomen, near my collar bones, and my lower back. It was only slightly itchy (I’ve attached a few pictures that I took from that time showing what it looked like as it was beginning).
Over time it gradually spread to cover much of my trunk (unfortunately I didn’t take pictures of this), but it looked like .
I thought it might’ve been related to a viral infection or something (even though I never felt sick), because I know that sometimes certain virus’ can give you rashes (the general term for this is a ‘‘).
When it didn’t go away after two weeks, I figured I should get myself checked out by a dermatologist. He diagnosed me with a skin condition called ‘.’ This is a condition that presents with a rash that only covers the trunk (exactly like mine), but the cause is unknown. No treatment is really needed, and it is supposed to go away by itself in 5-8 weeks.
One of the questions the dermatologist asked me was whether there was any thing new in my life. I mentioned that I’d been trying a ketogenic diet and have been in ketosis for the past few weeks. When I asked if there could be a connection, he emphatically said, “No. There is no relationship between your diet and this rash.”
Since he was so confident, I took what he said at face value and continued to chug along hoping for the rash to disappear. By the time week 5 rolled around the rash had waxed and waned a bit, but never really went away. About 8 weeks later it almost completely went away. I was pretty relieved at this point.
Unfortunately about a week later it came back with a vengeance.
The week when the rash started getting better and almost went away was when I was staying in NYC and started cheating there, eating a bunch of carbs (hard to resist NY cheesecake), causing me to fall out of ketosis. Then when I came back home and dug back into my getting my blood ketones back up, that’s when the rash reappeared!
So I did what any rational person would. I turned to google and found few interesting links. was the message thread that gave me my ‘Aha!” moment. The picture that was posted was almost identical to mine!
Turns out there is a skin condition that presents with the same rash that I had AND it can be brought on by ketosis! It’s called pruritis pigmentosa.
I had to prove this to myself, so I did what any diligent n=1 experimenter would do: I ate more carbs. The following morning, that rash got better. I ate more carbs. The rash got even better. This pattern continued for a few days until the rash had almost completely disappeared… and my ketones went waaaaaaay down.
Since there isn’t really much written about this condition, I did a quick on pubmed and will write brief summaries on the relevant papers:
Here is some general background:
Prurigo Pigmentosa (PP)
It’s interesting that despite the association found with ketosis, no clear explanation exists as to why. Why do ketones cause this rash? Is it because of the ketones themselves? Or because of some other factor that occur with the changes in metabolism seen with ketosis?
It seems like the answer to these questions is fairly far off. In the mean time, at least there are some effective treatments.
My Recommendation Based On My Own Experience and Research
I felt it was important to gather all this information in one place in case anyone else out there doing a very low carb or ketogenic diet has the same rash. I don’t want anyone else to be misdiagnosed, especially since there isn’t any lay literature out there, and many doctors don’t really know about this (as in my case).
If you’re in ketosis, the best way to treat this rash is simply to eat more carbs! It’s simple and cheap and it worked with me and many of the other individuals in the scientific literature, and hopefully it will work for you. If that doesn’t work, you can consider having your doctor try some of the medications listed above. Feel free to send them to this post since I tried to provide easy links to the source papers.
UPDATE:
I wrote a followup article I wrote with a . If you want to read any of my other thoughts on the keto rash and any new posts I wrote you can check them out .
UPDATE 9/15/2014:
Just launched which is where I will continue to post the most up to date research on this topic. I want to make it the most comprehensive resource available on the keto rash. I’ve also setup forums and a facebook group for people to discuss their own experiences. Head on over to check it out.
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