Keto rash – why some people itch on low carb, and what to do about it

Keto Rash

Typical locations of a keto rash

This is not a common problem on low carb or keto, but for the few people experiencing it, it can be really annoying: Itching.

This itching – sometimes called the “keto rash1 – can be troublesome, sometimes even interrupting sleep. The itching and rash are almost always symmetrical on both sides of the body. It most often develops over the chest, back, armpits and sometimes in the neck (see image above).

What is the reason for this problem, and how can it be cured?

There are many posts about this online, and many different theories. The time has come to make it simple, Diet Doctor style. Here’s everything you need to know.


The cause of the keto rash

SweatWhile there are dozens of theories about this problem, each more weird and unlikely than the next, we believe there’s a very simple answer. This is based on many people’s experiences,2 and the limited scientific studies available.3

Here are the clues, and the conclusion:

  • The itching usually starts soon after people get into ketosis. It stops within a day or so if people eat more carbs and exit ketosis.
  • It can often get worse in hot weather, or after exercising.
  • The usual distribution of the itch and rash matches areas where sweat can accumulate.
  • When in ketosis sweat can contain the ketone body acetone.
  • Acetone can be irritating at high concentrations.

I think there is good reason to believe that the itching that some people experience in ketosis is caused by ketones in sweat, perhaps as this dries on the body.



How to cure the keto rash

There are several things you can do to cure keto rash:

  1. Clothing: Wear comfortable clothing for the climate, so that you don’t sweat more than necessary. Use air conditioning when appropriate.
  2. Shower: After exercising it might help to take a shower – after you’re finished sweating.
  3. Change exercise plans: If the itching is really troubling you might want to skip exercise for a few days, or do something like brief weight training that does not produce perspiration.
  4. Exit ketosis: If the the steps above are not effective enough, exiting ketosis will reliably cure the issue within a day or two. This can be done by eating about 50 grams of carbs or more every day. To still get most of the benefits of a keto diet – at least for weight loss and type 2 diabetes reversal – you can do a more liberal low-carb diet (50-100 grams of carbs per day) and add intermittent fasting.
  5. Other treatments: There are many other treatments suggested online; like antibiotics taken for weeks or months and/or special creams. These will likely offer temporary relief at best.4 We definitely advise not to use oral antibiotics, as the side effects and risks are much worse than the doubtful and temporary benefits. Steroids, anti-fungal creams and anti-histamines appear not to be effective at all. There’s a safe, simple and free solution if you need it – number four, above. Use that instead.



What’s next?

If you get rid of the keto rash by exiting ketosis, can you ever use ketosis again? The answer is likely yes.

If you felt great in ketosis and had a lot of benefits, you may want to try again. The keto rash may stay away. Some people appear to get it only once, or only early in ketosis, when first starting out on a low-carb diet (given time, the body may excrete fewer ketones in the sweat). Remember, most people in ketosis don’t get the rash at all.

Keep the advice above in mind. And if all else fails, just eat a bit more carbs and the problem will go away.


Have you experienced keto rash? Do you want to share what helped and what did not? Feel free to leave a comment below!



  1. Another name that is sometimes used for this condition is “Prurigo pigmentosa“.

    The name means that it itches (“prurigo”), and that long-term, after many weeks, it can result in increased pigmentation (“pigmentosa”) in the affected skin area, looking like darker patches.

    This increased pigmentation, should it occur, fades very slowly after the rash is cured.

  2. Here are a few places to read about people’s experiences with keto rash:

  3. Here are a few relevant studies:

  4. This study references the experience of treating the keto rash (prurigo pigmentosa) with antibiotics. It did have an effect – possibly due to anti-inflammatory properties – but once the treatment was stopped the rash reappeared.

    J Dermatol. 2012: Prurigo pigmentosa: clinicopathological study and analysis of 50 cases in Korea.


Top comment

  1. Justin
    Good to finally see *something* written about this. I remember being unable to find anything when it happened to me in 2014. Read a lot about skin conditions, tried various antifungal creams, coconut and tea tea oil. Eventually had to admit the obvious source, my recent change to a ketogenic diet. I had the itch under my armpits and abdomen. It was intense. Not "troublesome". And it receded almost as soon as I began eating carbs. I only managed 7-8 weeks in a ketogenic state before I couldn't take the itching any more.

    It was too bad as I really enjoyed the ketogenic diet, felt less drowsy, and much better GI function (less gas, cramps, diahrea). Also was forced to eat more vegetables and nutritionally rich foods.

    Interesting idea that it could be related to acetone/ketone presence in sweat. I had figured it was related to the affect low blood sugar has on the adrenal gland, and how long term elevated cortisol might disrupt the immune system. The rash being some adverse inflammation as it's very similar to hives.

    I would love to see some proper research done on this. Heck, I would love to be the one doing it.

    Excellent article. Thank you.

    Reply: #255
    Read more →
1 2 3 4 5 6

All comments

  1. Corinne Nokel
    I have experienced the keto rash various times and yep, Aloe gel right from the plant helps soothe the itch ... I figure that our fat cells are the depository for toxins and starting ketosis - opening up the body fat cells at a larger scale and often after decades - releases toxins, which requires, that we take some form of binders for heavy metals etc. during the beginning. I started taking gluthathion and chlorella to support detox and things are getting better. Bentonite clay or zeolite are good, too.
    Enjoying feeling utterly well and cleansed on the inside... Happy Journey to a new level of well-being!

    P.S.: Dr. Mercola and Dr. Gundry talk about this phenomena a lot: Heavy metals can circulate in the bloodstream for more than a year if ignored, after weightloss. There is also a study on sea animals as well that relied and lived on ther body fat for a period of time and had drastically elevated levels of toxins and heavy metals in their bloodstream.

    Replies: #263, #264
  2. Rhonda Mojica
    Hi, I have done this low carb diet 5 times now and every time the first place I get itchy is my inner arm. Its a spot I must sweat a lot in. I love how I feel on Ketosis but this rash that has now spread to the other spot shown on this site, is really uncomfortable and annoying at work. I also have a welt on my forehead that I’m hoping disappears soon. 😳
  3. Marva
    Thanks to the advice on trying the fiber, psyllium husk, xanthum gum etc.. I have those on hand and use them occasionally in baking keto goods. I've had this keto rash before when in Ketosis and it was much worse, more like fungal rash, very weepy and mostly in my arm pits. Using antifungal creams did help a lot but it didn't go away until I started using bile salts. This time around it covers most of my body. Legs, arms neck and face. I'm so grateful to not have it on my back where I would find it hard to get relief with itching, haha! However it is insatiably itchy, it is not weepy and painful. Like many on here I have had such great results with the ketogenic way of eating, it's not an option for me to add carbs. The benefits far outweigh the irritating itching which I know will go away in time. Other than the rash I feel the best I've ever felt anytime in my life. I'm hoping the extra fiber and maybe some bile salts ( need to purchase) is going to help to speed this along out of my system. A big thanks to those who have shared their advice and remedies that have helped. I will post back in a few weeks and let everyone know if I found relief with extra fiber.
  4. 1 comment removed
  5. Ellen
    Wow your story sounds just like mine. Today is feb 21, 2020 and started keto jan1, 2020. About 8 weeks. The itch started about 1 week in and hasn’t stopped since. Today it was so bad that i have decided keto isn’t for me. I am going to increase my carbs and just do it slow. Never ever again will i indulge in carbs as i did but ten carbs a day isn’t good for my body. Hence the itch. And it’s such an intense itch it’s insatiable. I have scars all over from it and you’re right. They are hives. I wish there was more information on it. I’ve tried everything. Only thing that helped a bit was Benadryl cream. If you have received more information on this, i would love to hear it.
  6. Helen Batting
    Keto sweat is much less acidic than normal sweat, which upsets the ph balance of your skin and allows the wrong bacteria to grow. I live in South Africa which is sometimes hotter than comfortable for me and I often got keto rash, especially if I exercised. I have cured my rash (and that of my daughter and a cyclist friend) by using vinegar! Normal spirit vinegar is fine, you are making your skin acidic, not nourishing it. I just wipe it on after a shower while still wet. I do my head, chest , back and upper arms. I rinse my exercise bras in a vinegar solution. I have been in ketosis for years, and never needed to go off it, by doing this. My daughter scratched hers and developed ugly sores but they cleared up in less than a week.
  7. Armando Castillo
    Hello Michel C. I too have the keto rash. What brand/product of bile salt do u use? As well as the black seed oil.


    Reply: #259
  8. PatCalhoun
    How much and how do you use the psyllium husk and bile salts for those who said they helped?!
  9. Michael C
    @ Armando, Here is the one I used:
    Kiva Black Seed Oil - Organic,...

    However I think there are many brands and not too critical which one. It’s fairly common. Can also buy at Whole Foods.

  10. 2 comments removed
  11. therorichs
    I only got keto rash after about 10 weeks and the rash is heaviest on my shins, with only minor itching and very light rash on my torso, so I'm fairly atypical. I have had it now for 3 months. At times, esp when fasting, it gets very inflamed and vcauses oedema in my feet. I have tried many things including fresh aloe vera, black seed oil (topical and oral), tea tree oil, rose hip oil, apple cider vinegar (oral & topical), 200g berries daily - all to no avail. I eventually got so fed up I went to a doctor, who prescribed cortisone cream. This provided relief for almost 2 weeks, but the rash is now back. As I don't want to take antibiotics, I am now having 3 carb-heavy meals a day to see if it makes the rash better, as well as taking bentonite clay orally. and applying it topically. I hope something works. 1 week on carbs is making me crave being keto again.
  12. l.chouinard007
    Hi Corinne
    Do you have the links by any chance to these doctors on the heavy metal as well as the study? Thank you for sharing.
  13. l.chouinard007
    I have tried alcool in spray..seems to help a bit..calms down the rashes in armpits and below my breasts as well.
  14. shari l bryer
    I itch but I don't seem to have an actual rash
  15. Vik
    Is the issue with Keto in regards to dairy - lactose, or is it something else in dairy foods?
    Reply: #267
  16. Kristin Parker Team Diet Doctor

    Is the issue with Keto in regards to dairy - lactose, or is it something else in dairy foods?

    Yes, generally speaking. A lot of dairy has too much lactose, but cheese and heavy cream can be enjoyed in moderation.

1 2 3 4 5 6

Leave a reply

Reply to comment #0 by

Older posts