Low Carb

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, 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, I 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 I 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!



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  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.

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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.

    Read more →
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All Comments

  1. Carol
    I had this itch under my arms and breasts , I scratched so much I bruised myself, it drove me crazy. My ex -husband told me to get a lotion , called "Sarna" anti itch lotion . I got mine at Walmart , used it a few days and it went away.
  2. Jen
    I tried keto the first time 2 years ago. Within a week I started seeing the rash. As I worked out it got much worse. I became depressed after 6 months of very low carb and it still would not go away. It made me gave up. Low carb is what keeps me away from carbs in general. As soon as I try to up my carbs to keep the rash away it's hard for me to say no to cravings. Now I am back where I started eating carbs and feeling crappy. I can't wait for the day where I can do low carb and it stays away for good. ....
  3. julie
    I had the opposite effect. I was always itchy before going low carb, now I don't itch.
  4. Joakim
    I used to get the Keto rash aswell whenever I was going ketogenic. For me it was mostly under the armpits but also some just under the chest area.

    I found that eating alot of cabbage daily and avoiding certain foods like eggs, bacon, legumes cheese and most dairy products except for butter will allow me to go ketogenic without having the rash. I can eat unprocessed meat and fish and most vegetables.

    I dont know how or why this method work but for me it seems to be linked to bowel movements. Whenever I eat any of the foods that I dont tolerate when I'm ketogenic I will get constipated and the rash will come back.

    It certainly makes going ketogenic even harder than for most people but I think its still worth it for the 100% mental clarity and perfect body composition even when eating a very high calorie diet.

    Reply: #55
  5. Joakim
    In addition: It's not only when constipated btw, as I get the rash even from fasting for a prolonged time and even then cabbage seems to help and make the rash go away so maybe it is linked to gut flora in some way?
  6. natt
    Thank you for the information.
    I just started having rash last night after having LCHF for 10 days.
    At first I thought I am allergic to pumpkins seeds I ate the day before. I took antihistamine but it doesn't really help much. I still keep eating LCHF for a few days more to see whether the rash will go way. If not, I will try to eat more fruits or whole wheat toast to get more carb.
  7. Anik
    Oh my god i am so glad to find that site... I have rash like crazy... On my face, my arm, my hand... I love that diet... I was sure its was connect because its start in same time then i start to be in ketosis.... The doctor was tinking its was execma but the cortisone have no effect... I want to stay in ketosis but my skin is so bad...
  8. LCHF beginner
    I had very severe keto rash. It went over 2 months and stopped when I quit LCHF. It was very stressful and scaring because it looked there was something wrong with my body. At first, I thought I had a lymphadenitis or an atopy because the symptoms of both are similar. It got worse when I ate green bell peppers... no idea why... but sure because I tested it with my body. One more thing that I'm pretty sure, I felt my immune system was broken because my tongue was partially black, which is a sign of weak immune system. I assume a reason for my weak immune system is the meats with anti-probiotics. I've been taken probiotics over 3 years, and I had keto rash, so I think probiotics are not the treatment for keto rash.
  9. Alisha
    My rash looked like the picture above. When it started to reach my face I ingested a ton of carbs and broke out of ketosis. I was really enjoying it, too. I researched soooo much and like the Doc said, lots of ideas and opinions. I thought maybe it was gut health and yeast as so many had mentioned. I'm not a fan of antibiotics so I didn't go there. I stopped in October after 2 weeks, then have been taking several things to heal my gut, liver, gallbladder, and more. I JUST started back and am on day 8 and after my workout I found myself scratching my chest...then thought...oh crap...it's back. And sure enough...it is!! I was trying to stick to 20grams but it is hard to ingest that many carbs without anything that contains sugar so I was falling below about up to about 12grams. Today I up'd my carbs to 30grams thru nuts and now coconut water. I finger prick for ketones and I was at 1mmol yesterday, much lower than a few months back. But also, a few months back, I made sure I ingested 200grams of fat a day. This time, I'm taking in 75% of fat, but within my caloric restriction. If the 30grams of carbs does not work, I'll just have to try what the Doc said all together or go back to Paleo.
  10. Candace
    I've been in an out of ketosis several times over the past 2 years and I get a keto rash every single time. I've done a lot of reading on it and I think this theory holds the most weight. I only get it on my chest (between the breasts) so I put up with it because the results are totally worth the itch. And if I can see a silver lining -- it's saving me money on ketostix because I know I'm in ketosis based on how itchy this rash is!
  11. Cori
    This is my 2nd time in ketosis. I've now had the rash twice. The first time I thought it was shingles and so did my Dr. so I was prescribed anti-viral meds and took those. Apparently that was WRONG! I had no idea there was a "rash" associated with ketosis.

    The second one was like clock work. Exactly 5-6 days in and bam there it is. I'm going to try and suffer through it as long as it doesn't get really bad. I may also up my carbs on certain days just to see if I can keep it at bay a bit.

    It's really too bad cause this is the first time I've found a "diet" or healthy eating plan that works so well for me and I so love how I feel on this!

    I was happy to find this page and information. Thanks!

  12. MA in CA
    To add to the discussion re: why it happens.

    A possible mechanism, noted by a poster in the ketorash.com site was this: when in ketosis and exercising the body must convert fat to glucose - using gluconeogenesis process in the body.

    The original poster thought this is was the underlying mechanism for the rash. It happens that exercise makes more sweat... so it may appear that it's the sweat causing it, but actually it's a metabolic process.

    So what do we do about it? Will I get the same health benefits of keto diet if I'm not in ketosis?

    Here's the relevant post - excerpted: "During competition I slightly went over the intensity level, where my body is using only fat as fuel and I had to produce the needed carbs through gluconeogenesis. The needed protein my body took from my muscles (bad muscular recovery) and the higher rate of glucogenesis made the keto rash “explode”." http://theketorash.com/2015/12/07/doctor-germany-treated-keto-rash-st...

  13. Donna
    I found that my rash was caused by stevia sweetener which contains erythritol. I stopped eating anything with erythritol in it (many low carb protein bars) and I was cured. I hope this helps someone else as the rash and itching is terrible.
  14. Aryn
    I got it over xmas - having been lc and keto for over a year. ended up on steroids -- it started again recently -- my bet is it is an allergy to eggs. I fasted for two days, ate one meal both Monday and Tuesday of green salad with chicken, had an egg this morning and it started to itch mildly. Before you give up on keto, try getting rid of the most likely food issues (nightshade vegetables, eggs, caffeine, and etc) then add them in one food every couple of weeks until you find something that makes you react again. I'm delighted it isn't caffeine.
  15. Kathy
    Thank goodness I found this site. Every year I start the new year on a LCHF diet and exercise program and every year I get this rash, which I thought was a fungus from gym equipment. This year the rash started on my 18th day of dieting, the day after I started going to the gym. I have now had the rash for 11 days. I discovered this site yesterday and added carbs back into my diet and when I woke up today, my rash was half as bad as yesterday. I am going to continue adding carbs until the rash is gone and then cut back to 50, then 40, then 30 until I find the magic number to keep the rash away.
  16. Lois
    I also had the rash. I was so happy to see the photo as it is exactly what I was going through and couldn't figure out why. It was worse after exercise, so i made sure i showered, used body powder and took a Benadryl before bed and a slight increase in the total carbs i eat daily. This is The only thing that worked for me. Cortisone cream didn't help at all. Best of luck to all; if this helps anyone, i will be happy!
  17. Laura
    I was wondering why my heat rash from my tropical vacation 2 months ago was returning and spreading. Ha turns out to be keto rash. I am very afraid to lose my keto momentum only 10 days in and have been successful with CALOMINE LOTION so far. The Calomine lotion must be absorbing the acid because my décolletage, neck and throat are less bumpy less red and no longer itching. Yay!
  18. Loreen
    I'm dealing with the rash now. Paragraph 5 says to stay away from oral antibiotics that it will get worse. I will be having dental work (bone grafting) in a couple weeks and I know I will be put on oral antibiotics.
  19. Paulett
    I started on Doctor Furman "eat to live" diet. Six weeks of raw and steamed vegetables for lunch and dinner and fruits for breakfast. I also went to the gym four times a week. After returning from the Gym on day 7, I broke out in a rash. I thought it was something in the salad I ate. The itching was unbearable. I went to the dermatologist. She prescribed Clobetasol, no help. Five days of itching. My rash was also between my thighs. it's worst at nights. One night my husband and I went to the pharmacy at 2am as I could not sleep. I got a "CeraVe Itch Relief Moisturizing Lotion". It calm down the itching for two hours, then it erupted in uncontrollable itching again. I finally said it has something to do with my new diet so I had my bagel this morning and the itching calm for the first time in 5 days. So I Google "change in diet and rash" and came across this page. I screamed calling my husband as I never heard of ketosis. I am reading everyone comments and I am at awe. I am so sorry I did not Google it before eating that bagel, however I don't know if I can continue as the itching drove me crazy! Thanks for sharing.
    Reply: #82
  20. Pamela
    Yay I was right! I have been doing Keto for over a year and starting exercising, where I build up a sweat, a month ago. And along with the exercise has come this horrible itchy skin (no rash) on my torso especially where I sweat. I suspected it may have something to do with Keto and then read your article. Showering does help initally but I have other episodes of itchiness during the rest of the day and night. May try the coconut oil first. Have heard milk thistle may help too. Otherwise I may have to go out of Ketosis (heaven forbid)! Will keep you posted though. Thanks :0)
  21. Pamela Belsham
    PS I've tried the coconut oil liberally on itchy areas and it has worked! Give it a try!
  22. Veronica
    I think I might have it to, this is in the middle of my back.
    And it's a rash with small bumps. I put antibiotic cream
    On it, which it's clearing up.
  23. Jilma
    So I have to share my 20yr old daughter got the exact Keto Rash shown on the picture. 3-4 weeks into trying the LCHF/Ketogenic diet. I feel guilt over my shoulder for encouraging her to give this diet a shot. And now this happened. Her Dr didn't even know how or what caused it. She took a picture of her and sent it to the dermatologist and then they just referred her to Oral steroids and antibiotics!! Smh! Anyhow she's out of Ketosis and healing thank god! I have to say being on Ketosis works wonders, but definitely not for everyone, unless the individual is doing something wrong, but what is it? That's the million dollar question. What causes people to get a Rash on LCHF????
  24. Jilma
    I pray for everyone here that has gotten this aweful Rash. Hope we can find a fix to prevent anything like this happening to all who wants to live a healthy lifestyle ❤️
  25. Tim
    Apply brown Listerine, let dry...apply Tinactin. Works for me with immediate results. No idea why, suspect reaction to yeast die off...
  26. Saundra
    Benadryl does the trick to control the itch and rash.
  27. Sarah
    I don't have a rash like the picture but I itch all over and especially in the areas in the pic. I thought at first it was because I just insulated about 800 sq ft of an addition plus the ceiling so thought that the Roxul insulation fibers were in my clothes making me itch. I washed them several times but still itch. I thought maybe it was dry skin since it's winter and have put lotion on which helps some but the itchy feeling is still there if I give into it. My back, my legs, my hips, my chest, my neck....it's like an all over itch! I would need to douse myself in an anti itch cream! Nice to know I'm not crazy and that eating this way causes this reaction in lots of people. I'm in the 3rd week and still not losing much weight but I will press on til my birthday in a few weeks to see if another 5lbs will come off. I was hoping that I would lose 20lbs in 4-6 weeks but I'll be happy now if it's just 10
  28. Lisa
    I have a rash on chest and back and I am on keto diet. I put apple cider vinegar with the mother in it into a spray bottle and spray it on my back and chest. Burns a bit for a minute but definitely gives relief to the itching.
  29. Sandy
    Might not be relevant but I got a fungal infection in my armpits due to using a "crystal" deodorant, which creates an alkaline environment (bad for bacteria, good for fungus.) Nothing but nothing had the slightest effect on it...it caused peeling skin like a sunburn. Finally got the idea to try UV light on it. Sat in the sun with arms up for a few minutes a day for three or four days and zapped it. Eventually started using the crystal deodorant again and have not had a recurrence.
  30. Dirilis
    Hi everyone,

    Iv been doing keto diet for almost 3 months now. I had this rash in teo different times. First was almost 1 month after the diet and it was very minimal and it was only beside my neck in the upper shoulder in my left side. I did not break my diet i continued and gradualy it started to fade away. But now it came back again but also its spreading in my back as well. What i have noticed is as much as i sweat it starts itching. Also if you scratch it it will get even worse. But when i take a cold shower it will itch and it will be painfull little bit but it wil fade away after the shower. But when using a towel i dont scratch, i just put the towel against my skin and let it absorb the water. Also i try to fight it mentaly. By just trying to ignore to scratch my skin when i feel like i want to because it will make you scratch more and more.

    Once i have tried appricot oil on my skin it slowed down the itchiness and the redness of the rash. I dont know may br it had a reaction to the acitone in the skin?

  31. Geraldine Denise
    I've been following the Ketogenic way of eating now for more than a year.Didn't have any problems except Keto Flu' which was horrible, but I survived! I've cut out fruits entirely except for lemon , Avocados, and the occasional Grapefruit. Strawberries once in a blue moon. Being VERY careful with the quantities. I am only taking supplements, no medications, no drugs. I have developed a rash on my neck and chest. Looks like an allergic rash, but I'm beginning to think it must be due to being in Ketosis. Living in Rio De Janeiro, it's difficult to find the purple strips for my Keto thingy. Anyway I still have a few (3-4kgs) to lose & I'll be at my ideal weight. It's really a pain trying to figure out what is causing it, I stopped eating nuts, wonder if it's peanut butter? Ketosis?
  32. Geraldine Denise
    I shouldn't think you were in Ketosis if you were eating fruits and vegetables. All of which are pure Carbs! To be in Ketosis you eliminate fruit almost completely and vegetables to low carb veggies, all above the ground. Being "IN KETOSIS" you can only eat 20 carbs a day, net carbs eliminates the fibre. You would need to have had "Keto Flu" that happens when you first go into Ketosis and make you feel ill, headache and lethargic and a bit sick , surviving that you measure your ketones with six , or in Urine or a blood meter. Purple strips. BUT I don't think there'd be any chance you'd be in ketosis eating fruit & veggies. I only eat above the ground been leafed veggie(Squash has lots of carbs!) Only Avocado and lemons as seasoning, fruit once in a blue moon and then only berries.
    Ketosis requires action to Macronutrients, if you eat too much protein it takes you out of Ketosis. Fruits are natures candy, full of sugar! Especially modern day fruit.
  33. Dany
    Hi, I live in Townsville, tropical North Qld. I have been suffering terribly with the itch & scratch since commencing LCHF. I also do intermittent fasting but unlike the posts above my concern revolves around my head. My scalp itches intensely due to constant sweating due to temperature. It feels like I must have nits! Never had head lice in my life so I can't really compare. . I don't work out but do walk my dogs every morning and always am soaked with sweat by the time I get home. My head now, after a month, is covered with scabs and I am thinking I may have impetigo as a result of constantly scratching. I have changed shampoo etc but nothing seems to help. Antihistamines do help but make me sleepy so am loath to take until I have no option. Please don't tell me I have to cease this WOE! Any advice would be great. Thanks I. Advance!
    Reply: #84
  34. Dany,
    I'd suggest getting out of ketosis at least until your skin heals. Does not mean you have to quit low carb, just do a less strict version for a while (e.g. 75 grams of carbs per day)
  35. Tim
    Has anyone eles had luck with Sarna lotion, or other?
  36. margaret
    I too have the keto rash. I now try to eat a moderate carb diet. basing my carbs on apples pears and oranges in small amounts, and eating green based smoothies, ie wheat grass, kale zucinni and cucumber. though this does seem to help with relief, I still get itchy. So now I have added applying lovely coconut oil on my itchy spots, lol. That is helping too. I don't want to progress to having sores so I hope the rash will resolve. I did notice I got the rash when I added some organic collagen powder, so am wondering about decreasing my protein consumption. Any suggestion ? Thankyou! Love low carb. Makes me feel much better, and big improvement on my mood!
  37. Em
    My keto rash stopped!! Details below.

    The first time I tried Keto I got the rash. I had gone from low carb (under 100 g) to around under 40 g carbs and the rash appeared under my breasts, around my collarbone, and down the middle of my stomach. I attributed it to my diet change, as I haven't gotten a bad rash since I was a child. I googled "keto" and "rash" and came up with this site among many others. I ate a sweet potato and it cleared up by the next day.
    I attempted Keto again a couple weeks later, rash came back 2 days in, I ate a sweet potato, and it went away again.
    During this time I also had a ton of hunger, even though "Keto." What I found was that I was not truly eating Keto because I was only eyeballing my macros. I wasn't eating enough fat, and was eating too much protein. Every time I still felt hungry, I thought I needed stomach volume, so I'd add a beef patty or piece of chicken - I should have been adding fat. Psychologically I felt like I'd still be hungry if I did keto correctly, since fat does not have a lot of volume. So I avoided going full-on keto because I wanted to eat more.
    Finally I decided to really up the fat, because I was getting really sick of protein on this low carb (not really keto) diet. I really just wanted to stop eating all together as I was so bored with meals, that I really started piling on the fat. I've been able to do under 20g carbs a day and no keto rash with 2 things that may have helped me escape the rash: Keeping my servings of protein low (maybe 3-4 oz per meal), and my VEGGIES (with fat) very high. I eat 7-10 c of greens a day, and this is where my carbs come from. I don't know if there's something in the veggies that combats a rash or balances my body, or if it signifies too much protein and not enough fat. Or maybe my body finally did just adjust to ketosis.

  38. David Rowe
    I have been doing keto diet since middle of January 2017 and around first of march got the keto rash increased my carbs and it went a way. Then when I hit stopped losing weight I lowered my carbs again and now last Friday April 21 2017 the rash appeared again and by Sunday I have blisters on my back, butt, groin and privates.
    Went to Dr. yesterday and she said they looked like burns. I told her about doing keto but I think it went in one ear and out the other.
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