Keto Rash: What It Is and How to Prevent It

While not a common problem for those following a low-carb or keto diet, the keto rash is very unpleasant for those who are afflicted by it.

Waking up one morning to a red, itchy rash covering your neck and torso can be quite distressing.

The good news is that it isn’t something to really worry about. It is not dangerous.

However, if you are one of the few who has to deal with this annoying side effect, just knowing that isn’t going to help. Especially when you are kept up at night because of the itching, or having to cover up when you go out.

We are going to discuss how to treat the keto rash, as well as how to try to prevent it from appearing at all.

The Cause Of The Keto Rash

The keto rash happens to those who recently started the ketogenic diet. It is an inflammatory skin disorder that is quite rare, called prurigo pigmentosa.

It was first reported in Japan in 1971, and since then only 300 cases have been reported in Japan, and 50 cases outside of Japan.

It is most likely to occur in females around 25yrs old – in fact, it appears that women are twice as likely to be affected.

It tends to start on the neck, chest, and back (most prominently in the middle of the chest and back).

There are studies that show it might be caused by excessive ketone production. Research has also shown that inflammation causes the rash. This is due to something called ‘neutrophilic infiltration’ – which is an accumulation of a specific type of white blood cell.

Triggers For The Keto Rash

There is a variety of triggering factors that can possibly lead to the keto rash.

(While the exact cause of the keto rash is not known, research has shown links between prurigo pigmentosa and ketosis.)


The ketones produced by your body can cause inflammation which triggers the rash.

Excessive Fasting

During a fast, when blood sugar levels are low, your body goes into ketosis, which can trigger the rash.

Low-carb Diet

Rapid weight loss has been linked to the keto rash, and low-carb diets tend to lead to very quick weight loss.

Nutrient Deficiency

Excluding certain foods can lead to a nutrient deficiency. This deficiency could result in the keto rash.


An allergic response to certain foods could lead to you developing the keto rash.

What Are The Symptoms Of The Keto Rash

The keto rash looks very similar to eczema or dermatitis.

The skin is itchy and raised, with the bumps ranging from a pale pink to red, or even a brownish color.

The rash tends to form in a symmetrical pattern on either side of the body. In the early stages, the rash will be light and look more like scratch marks. As the rash develops, the lesions go darker and may even become infected.

Strenuous exercise or exposure to heat, moisture, and friction can worsen the rash.

The rash can last from a couple weeks to several months. It varies from person to person. And if you’re one of the unlucky few, it could appear each time you go into ketosis.

The keto rash is not dangerous or life-threatening, so don’t be alarmed if you have developed it. In the next section, we will discuss how to treat it.

How To Treat The Keto Rash

I’d like to be able to say – how to ‘cure’ the keto rash, but as we don’t yet know the exact cause of the keto rash, there isn’t necessarily one best cure.

However – you can treat it with these research-backed methods to help alleviate your symptoms.

Wait It Out

When you first notice the rash, try not to panic.

The rash may just disappear on its own accord after a while. Especially if this is your first time following a very low-carb diet, your body may just need some time to adjust.

The more time your body spends in ketosis, the more it adapts to being in that state.

If, however, after a couple weeks the rash is still there and showing no signs of improving, you can try some of the other tips on this list.

Add More Carbs

Reintroduce carbs into your diet just enough to take you out of ketosis. Do this for a few days to see if the rash subsides.

If it does, lower your carbs again to enter ketosis. If the rash reappears, then it is possible that your body is sensitive to ketones.

If this is the case for you, rather than following a strict low-carb or keto diet, with 20-50 grams of carbs per day, you can consider a low-carb diet of around 50-100 grams of carbs per day. If you combine it with intermittent fasting, you can still get some of the benefits of ketosis.

Eliminate Food Allergens

If you have started eating new foods since starting the keto diet, you may be having a reaction.

Foods that commonly cause reactions are dairy, eggs, seafood, peanuts, and other nuts.

Try an elimination diet to find the culprit. First – remove all of these foods from your diet for three to four weeks. Then gradually reintroduce them one-by-one, one food per week. Track your process throughout the week. If there are no new symptoms, then move on to the next food.

Take Nutritional Supplements

There may be a chance that you are deficient in certain minerals or vitamins – even without being on the keto diet. But the chance of that becomes higher when on a restricted diet such as keto.

Take supplements to cover any vitamins and minerals you may not be getting enough of, such as Omega-3’s, Vitamins D and A, and sodium, potassium and magnesium.

Also, ensure that you are drinking enough water. A low-carb diet leads to a loss of fluids, which then increases the concentration of acetone.

Minimize Sweating

If it has been hot, or you have been doing strenuous enough exercise to cause you to sweat, around the same time that the rash started, then your sweat may be affecting your skin.

The acetone in sweat is a major trigger for a rash. Try to avoid situations that will cause sweating.

Wear light clothing (moisture-wicking material will help keep the sweat off your skin), and try to avoid heavy workouts for a few days. If you do end up sweating, shower directly afterward to wash off the sweat.

Reduce Your Stress

Emotional stress is linked to skin inflammation. I know it easier said than done to reduce stress, but learning how to deal with stress is beneficial in all areas of life.

Try yoga, or learn some breathing or meditation techniques.

How To Prevent The Keto Rash

The first – and possibly most important – step, is to transition to the ketogenic diet slowly. Ideally over a few weeks.

You may want to dive in headfirst and get rid of all the moderate and high-carb foods in your cupboards. But if you jump from a high-carb to a low-carb diet very suddenly, it could cause your body stress and trigger the rash reaction.

You can start by eliminating sweets and chocolate, then processed carbs, then lentils, legumes and whole grains, and so on.

As you are gradually removing the carbohydrates, slowly add in healthy fats.

Keep an eye on your skin as you enter ketosis – as soon as it starts getting dry and itchy, increase your carb intake a little.

At the same time as you are transitioning, add supplements to your diet. And don’t forget to drink plenty of water.

By transitioning slowly, your body will be better able to handle ketone production and your body will enter ketosis more prepared.

Everybody Is Different

One of the toughest things about the ketogenic diet that many people struggle with is that all of our bodies are different and therefore our bodies will react differently when on the diet.

You might read how someone was able to lose 10 lbs in 1 week and got into ketosis after just 3 days – with no side effects – while you’ve been struggling for 3+ weeks to make the pee strip turn darker, and dealing with a rash to boot!

There is no step-by-step formula to get into ketosis that can apply to everybody.

Some people need to eat fewer carbs than others while some might need to incorporate exercise into their daily routine sooner.

The point is that when you get rid of sugars and lower the number of carbs you consume you are doing a great thing for your body anyways. If you can focus on those things and let everything else happen naturally you’ll find yourself in a much better state of mind.