If you have recently started the keto diet or have been living the low-carb lifestyle for a while now, you may have noticed that you have developed some skin sensitivities and even a rash. Worried? There is no need to be! Keto rash is very rare but is also explainable and treatable. And no, it doesn’t mean you are doing anything wrong!
Rashes are often worrying, and as keto rash can be accompanied by itching, it can be annoying. Besides, having keto rash on (your) face could be a cause of embarrassment.
The keto diet, where you reduce your carb intake to 50 grams per day or less and eat more fat and moderate amounts of protein, is a very effective way to burn fat and lose weight. However, that effectiveness comes at a cost – eating very few carbs changes how your body works. These changes can sometimes be accompanied by a range of side-effects, and ketosis rash is one of them.
Has your keto diet triggered a rash? Or do you just want to make sure you don’t experience this mildly-irritating symptom? Don’t worry – we’ve got the solution!

What is keto rash?
Rashes come in many varieties. Some are accompanied by itching, raised bumps, redness, pustules, and a host of other additional symptoms. Before trying to treat keto rash, it’s important to make sure that is what is affecting you. After all, rashes can be caused by lots of other triggers, not just the keto diet.
Keto rash’s scientific name is prurigo pigmentosa. This condition is not specific to keto, and there are other reasons that you may develop it. However, if you are following the keto diet, it’s possible that the keto diet is the cause according to the research.
Prurigo pigmentosa is an inflammatory skin condition resulting in a rash that consists of itchy, raised bumps, which generally appear on the back, chest, neck, or armpit area. Keto rash can easily be confused for dermatitis or eczema as it looks very similar. But, if you don’t usually have those conditions and are currently on a keto diet, those causes are typically easy to exclude.
Keto rash mostly starts with small bumps. However, after a short time, those bumps can begin to worsen, fusing into a bigger network of inflammation. Keto rash often appears symmetrically, i.e., on both sides of the body equally.
Keto rash also tends to come, go, and come back again. It may leave behind a pattern of darkened skin or hyperpigmentation, which lasts longer than the actual rash. The skin may also become scaly as the rash heals.
To summarize, keto rash:
- Starts with inflamed, itchy skin with raised spots forming a broader pattern
- The rash is usually accompanied by itching
- The spots are mostly symmetrical and occur on the back, abdomen, chest, and armpits
- Keto rash usually comes and goes
- As it heals, the keto rash can become scaly and often leaves dark spots or hyperpigmentation which will take time to normalize
It’s worth mentioning at this point that keto rash is a real problem, but it’s also very rare. Very few keto dieters experience keto rash, and while accurate statistics are hard to pin down, estimates suggest that there have only been about 200 cases ever documented, and most of these occurred in Japan. Women are more likely to develop keto rash than men but, even then, the risk is very VERY low.
What causes keto rash
Like so many rashes, the exact cause of keto rash is unclear. It’s so rare that it’s not really been studied to any significant degree. All we do know is that several contributing factors may increase your susceptibility to developing this unusual keto side effect.
Current keto rash suspects include:
Ketones released through sweat cause irritation – ketones, your body’s source of energy when you eliminate carbs from your diet, are excreted in your urine and also leave your body when you sweat. Ketones are acidic and, as they pass through your skin, could cause irritation and an accompanying rash. If you live somewhere warm or exercise a lot, you may sweat more than usual, triggering keto rash in the process.
An allergic reaction – going keto means excluding certain foods and replacing them with alternatives that may be unusual to you. This could trigger a previously-unknown food allergy.
Nutrient deficiencies – the keto diet is usually very healthy, increasing your intake of healthy fats, and non-starchy vegetables. However, it’s entirely possible to follow the keto diet and eat unhealthily. For example, instead of fish and chicken, you could eat lots of processed deli meats instead. “Dirty keto” could result in nutrient deficiencies, leading to skin issues. After all, your skin is just another organ, and if it isn’t getting the nutrients it needs, it may respond with rashes.
Toxins irritating the skin – the keto diet is excellent for burning fat. In fact, cutting carbs from your diet will turn you into a fat-burning machine. Fat loss is often very rapid on the keto diet. Your fat is not just a source of unused energy; it is also where your body stores a lot of its toxins. As you lose fat, these toxins are released. They spill into your bloodstream, irritating the blood vessels, and potentially resulting in a rash. Rapid fat loss means a slew of toxins is released all at the same time.
Increased sensitivity to external irritants – big dietary changes may increase your sensitivity to external irritants such as laundry powder, fragranced soaps, chlorinated pool water, cleaning products, or perfumes. Such irritants can cause allergic reactions and rashes.
Increased sensitivity to temperature changes – your skin reacts to temperature changes. Normally, these changes go unnoticed. However, with prurigo pigmentosa, changes in temperature may cause irritation. For example, if you quickly go from feeling very cold to very hot, your skin may become reddened and inflamed. This is not usually an issue but, if you have keto rash, your skin may respond more dramatically.
As you can see, there are lots of potential triggers for keto rash, but they can all be linked to living the very low-carb lifestyle. Remember though, keto diet rash is very rare, and there are ways to treat and even prevent it. Also, just because you have a rash on keto doesn’t mean you have keto rash. There are lots of potential causes of skin inflammation and itchiness.
How long does keto rash last?
Keto rash, while incredibly uncommon, is also usually very short-lived. It can come and go in a day. In some instances, it appears shortly after entering full ketosis, i.e., after a week or so of quitting carbs. Other people have developed keto rash earlier or much later than this.
And as for how long keto rash lasts? That’s impossible to answer. Some sufferers have reported that their skin cleared up in a matter of hours or just a few days. In other cases, the rash has lasted a week or so. Some people report that their keto rash comes, goes, and comes back again. Other sufferers get it once, and it never reoccurs.
The long and short of keto rash is that we don’t really know enough about it to say how long it will last. It might be a few hours, a couple of days, or even a week or two. It might come back, or it might not. It’s just the luck of the draw!
The one thing we do know is that several practical interventions can help treat or even prevent keto rash.
How to treat keto rash
If you are one of the unlucky few and find yourself suffering from keto rash, the first thing to do is not worry. Stress and anxiety will make things worse. Instead, just follow these easy-to-implement action points.
1. Let keto rash heal on its own
Don’t be tempted to slather your skin in lotions, start taking anti-histamines, or wrap your skin in bandages. Instead, try and let your rash heal by itself. Most keto rash sufferers report that it usually heals all by itself. However, if your rash lasts more than a couple of weeks, it may be time to try some additional options.
2. Increase your carb intake
Because keto rash may be linked to an excess of ketones, it makes sense that reducing the ketone concentration in your body could help alleviate your symptoms. Don’t ditch your diet entirely. Instead, slightly and gradually increase your carb intake. If you are currently eating 30 grams of carbs per day, try consuming 50 grams instead. If that doesn’t do the trick, increase your intake to 75 grams.
You may find that simply increasing your carb intake slightly is all that you need to do to cure your keto rash. If, however, this doesn’t work, drop your carb intake again to make the most of the fat-burning effect of ketones.
If you find that your rash vanishes when you increase your carb intake, you may benefit from following a cyclic ketogenic diet, or CKD for short. With this keto variant, you go keto for 5-6 days per week, and then break ketosis with 1-2 days of more carbs. This may help you avoid triggering a keto rash.
3. Eliminate potential allergens from your diet
Unfortunately, this is not a quick or easy process, but it may be a necessary one of you have a long-lasting keto rash. Identify potential allergens in your diet and eliminate them one-by-one to see how your skin responds. Common sources of allergy include:
- Dairy (e.g., cottage cheese, full-fat yogurt, hard cheese)
- Eggs
- Fish (e.g., tuna, mackerel, salmon)
- Shellfish (e.g., oysters, clams, crab, prawns)
- Tree nuts (e.g., macadamia, almonds, brazil)
- Peanuts (oil, butter, and the nuts themselves)
Remember; you might have multiple allergy triggers so don’t just stop this process if you find a potential suspect – keep going to eliminate all allergens.
4. Pump up your intake of skin-healing nutrients
Skin issues can be caused by nutrient deficiencies, so make sure you are providing your skin with everything it needs to be healthy. Forget about things like lotions – they do not penetrate deep enough to be of much use. Instead, nourish your skin from within. Essential skin-friendly nutrients that may be scarce on the keto diet include:
Minerals: Increase your intake of sodium, potassium, and magnesium. You tend to excrete more of these substances as you enter ketosis. Get enough of each one because they are vital for multiple metabolic functions. Consider making and taking some homemade ketoade to supply your body with the minerals it needs.
Vitamins: Vitamins D, C, and A, and niacin are just four of vitamins that are required for skin health. Make sure you consume plenty of keto-friendly vegetables to get enough vitamins in your diet. Consider adding vitamin supplements if you feel you need extra nutrients.
Omega-3s: Omega-3 fatty acids, also known as fish oils, play an important role in controlling inflammation. Treat your reddening rash from within by eating more oily fish or using an omega-3 supplement. Take about 500-1000mg per day for best results.
Water: Dehydration can have a noticeable effect on your skin health. It makes it less elastic and also increases the concentration of ketones and acetone in your sweat – a suspected cause of keto rash. Drinking more water is good for all aspects of your skin health, and that includes reducing inflammation.
5. If all else fails, ask your doctor about antibiotics
If your skin rash does not respond to these straightforward interventions, you may need antibiotics. The best antibiotics for keto rash are:
While antibiotics can help heal keto rash, it may not stop it from returning. This type of medication seems to address the symptoms of keto rash but does not address the cause. There may also be side-effects when using antibiotics, so make sure you discuss all aspects of their use with your doctor.
How to avoid keto rash in the first place
An ounce of prevention is worth a pound of cure, or so the saying goes. Here are a few strategies that may help you avoid keto rash in the first place.
1. Ease into ketosis – if keto is new to you or you are returning to keto after a long break, avoid shocking your body too much by easing yourself into ketosis. Instead of dropping your carb intake to 20-30 grams per day overnight, reduce your intake over several weeks instead. In other words, go low-carb before you go no-carb.
2. Increases your intake of skin-friendly nutrients before you need them – don’t wait for keto rash to develop. Instead, start your skin-friendly eating regimen well in advance. Make sure you eat plenty of oily fish, nuts, and vegetables as well as drink adequate amounts of water.
3. Eliminate potential allergens before you start your keto diet – if ketosis increases your potential for developing skin sensitivities, avoid this problem from the start of your diet by avoiding known triggers in the first place. Use fragrance-free soaps and deodorants, choose detergents and fabric conditioners made for sensitive skin, and generally avoid the things that could trigger an allergic reaction. You may be overcompensating but, if you want to prevent keto rash, it’s better to be safe than sorry.
Conclusion
It’s a good thing that keto rash is so rare because if it was a common side-effect of the keto diet, it could be enough to put people off the low-carb lifestyle. As it is, the chances of suffering from keto rash are very low, and it’s generally nothing more than a minor annoyance that can usually be treated easily or prevented entirely.
If you do develop a rash during keto, put the action points in this article into practice, and you should find your skin problems quickly vanish. However, if you are worried that your rash is not related to your diet or it does not respond to your homecare treatments, you should not hesitate to speak to your doctor.
Above all, remember that, like all of the other symptoms of keto flu, keto rash is just an indicator that your diet is working – you are in ketosis and burning fat faster than ever before. Your rash is temporary and should disappear all by itself as you get used to your new ketogenic state.