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.

Comments

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.

302 comments

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.

    Replies: #255, #294
    Read more →
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All comments

  1. Ruth Maher-Heslip
    I’m on Day 7 and a rash has appeared identical on both sides underneath both breaths. Feel great apart from this, it’s only mildly itchy at the moment but I do quite high intensity excercise so think this may helped the rash along. Could I be in Ketosis after just 7 days?? I’ve been strict but I expected it to take longer...hopefully the rash doesn’t get worse!! Glad I found a reason for it quickly as I was worried it was something like shingles
    Reply: #302
  2. Crystal Pullen Team Diet Doctor

    I’m on Day 7 and a rash has appeared identical on both sides underneath both breaths. Feel great apart from this, it’s only mildly itchy at the moment but I do quite high intensity excercise so think this may helped the rash along. Could I be in Ketosis after just 7 days?? I’ve been strict but I expected it to take longer...hopefully the rash doesn’t get worse!! Glad I found a reason for it quickly as I was worried it was something like shingles

    The amount of time ketosis takes varies from person to person. Showering as soon as possible after your workout may help.

    Reply: #303
  3. Lissa
    I have done the medical weight loss keto diet once and never had issues with a rash. I’m wondering if how I started it this time could be why I developed a large rash on both inner forearms, under upper arms, neck, chest and parts of my upper front thighs. I originally thought it contributed to severe stress I was under at work. During riots and protests our building was surrounded and for one week everyone was scared when leaving and evening the building and then to deal with vile verbal abuse from all over the world. I went to my PCP and she gave me prednisone and hydroxyzine which seemed to have helped a lot over the last 4 days. Although, now that I think about it. I started using Pruivit ketones. It’s a challenge where you drink straight ketones to get you into ketosis quicker. I drank it the week before the chaos at work began and stopped abruptly when focus went off food and drink to work work work. Anyone try pruivit?
  4. Shirlee Willis
    I have had terrible itchy skin for weeks now. I’ve been on Keto diet since June first and have lost 16 lbs. My rash looks like bites.. theyIt’s so bad I bleed. They are now head to toe literally- in my hair down my back arms, legs and on top of my feet. Itching is worse at night and where I lay. Can’t sleep. My dermatologist is baffled.. I’m going to share this with him. Doctors need to know about this.
    I am going to increase my carb intake and hope it helps. Still No sugar! Thanks for all your comments I’m game to try anything at this point.
    Reply: #305
  5. Kerry Merritt Team Diet Doctor

    I have had terrible itchy skin for weeks now. I’ve been on Keto diet since June first and have lost 16 lbs. My rash looks like bites.. theyIt’s so bad I bleed. They are now head to toe literally- in my hair down my back arms, legs and on top of my feet. Itching is worse at night and where I lay. Can’t sleep. My dermatologist is baffled.. I’m going to share this with him. Doctors need to know about this.
    I am going to increase my carb intake and hope it helps. Still No sugar! Thanks for all your comments I’m game to try anything at this point.

    Best wishes to you, Shirlee! We hope our tips will be helpful for you!

  6. Brisa
    I was 6 months into keto dieting when I had 3 cheat days in a row. After that, a rash started under both of my underarms. I had just swithch the deodorant and tought that that was the reason, but I went back to my old one and that did not work. It has been a month or so and the rash is still there. I have big red patches that each ans hurt. I have not figured out when they get worse. I have noticed that my scalp itches, my legs ans face each too. I only feel little bumps on my legs but notting as my underarms. I have only applyed coconut oil and it helps a little with tje itch. I will try vinager, quercetin and see what happens.
  7. Nel Acob
    When I started keto it took about 3 weeks for rash to appear. It was horrible, itchy and kept me up at night. I tried all suggestions you can find - blackseed oil, bile salt, baking soda, coconut oil but found no relief. I resorted to increasing my carb to 30-40g a day and that seemed to do the trick. Its beenabout 6 weeks since I started ketogenic diet and anytime I drop lower than 20g carbs a day, they start to reappear. I’ve been testing with keto mojo so I know I’ve stayed in ketosis the whole time. I just need to make sure I find that sweet spot or the plague comes back. I also found that somehow they are triggered during my cycle. Not sure if that’s just a coincidence but found another article that proves there’s a correlation. I don’t ever want to stop this lifestyle but it’s definitely adding another layer of frustration when I have to deal with this rash throughout my journey. Would appreciate any other suggestion..
    Reply: #308
  8. Crystal Pullen Team Diet Doctor

    When I started keto it took about 3 weeks for rash to appear. It was horrible, itchy and kept me up at night. I tried all suggestions you can find - blackseed oil, bile salt, baking soda, coconut oil but found no relief. I resorted to increasing my carb to 30-40g a day and that seemed to do the trick. Its beenabout 6 weeks since I started ketogenic diet and anytime I drop lower than 20g carbs a day, they start to reappear. I’ve been testing with keto mojo so I know I’ve stayed in ketosis the whole time. I just need to make sure I find that sweet spot or the plague comes back. I also found that somehow they are triggered during my cycle. Not sure if that’s just a coincidence but found another article that proves there’s a correlation. I don’t ever want to stop this lifestyle but it’s definitely adding another layer of frustration when I have to deal with this rash throughout my journey. Would appreciate any other suggestion..

    I am sorry you continue to suffer from this. The Diet Doctor suggestions are included in the article under "How to cure the keto rash".

  9. Kat
    Thanks for the info.i have the rash on my back and I’m not even on Keto diet. I eat less for the past week and removed sugar and dairy in my diet. Would this be a Keto rash?
    Reply: #310
  10. Kristin Parker Team Diet Doctor

    Thanks for the info.i have the rash on my back and I’m not even on Keto diet. I eat less for the past week and removed sugar and dairy in my diet. Would this be a Keto rash?

    If you are not eating keto and not in ketosis then it's not likely to be keto rash. If it doesn't resolve soon, please check in with your doctor.

  11. Maggy Holt
    Been on the keto diet since August 20th so just over 8 weeks ..... I had this rash that was itchy and driving me crazy, I thought it was my fabric softener at first until I stumbled upon this web page ..... since reading all the posts I decided to take some black seed oil orally, 1 TSP daily for a few days then increased it to 2, luckily the itch scratch rash begun to ease ..... This Sunday I will be increasing my carbs to between 50 -100 as my body may need a bit of a boost to help the situation, I've been very strict at the beginning of the diet sticking to 10 net carbs for most days with the odd few times increasing to 20, I've managed to lose 20 lbs so far but need to double that figure ..... I can achieve my goal but only with this KETO DIET it's working so well for me, this Rash will not stop me
  12. M
    Many keto foods are high in histamine, so the keto rash is most likely due to high histamine levels. Find lists of high histamine foods and low histamine foods. Avoid/minimize high histamine foods and eat more low histamine foods. It works.
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