What's Keto Rash and How to Prevent It?
Updated: Oct 28, 2019
Picture this. You’ve just sat down to the kitchen table. Eggs and bacon are sizzling in front of you. The aroma of your favorite butter coffee wafts cartoon-like from the mug all the way to your nose.
You’ve started the ketogenic diet and things have been going well. You’re using MCT oil. You’re hitting the high-fat, low-carb, moderate-protein macronutrient ratios. Maybe you’ve even tried incorporating intermittent fasting into the routine.
But suddenly, there’s an itch.
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Not an itch for a doughnut, but an itchy feeling all over your skin.
Maybe you didn’t notice before, but now you realize there’s a rash and on your chest, stomach or back.
What in the world could be causing this level of discomfort?
It could be the first signs of “keto rash.”
Let’s explore what causes keto rash, and look at some ways to both prevent and cure it.
You Body’s Reaction to Carb Depletion
The ketogenic diet is a low-carb, moderation protein, high-fat diet with one goal—enhance ketone production.
Typically the body is predesigned to run on glucose (carbohydrates) as its main energy source. In the standard Western Diet, about half of your macronutrients come from carbohydrates. But as you decrease carbohydrate intake, the body (and brain) must turn to alternate fuel sources.
When compared to carbohydrates, our bodies store larger amounts of fat. The problem with fat is that the brain can’t use it as energy; the brain loves carbs.
So in order to provide our brains with fuel, we evolved to create ketones for fuel from the breakdown of fatty acids (ketones cross the blood-brain barrier; fat does not).
Ketones are a highly-efficient energy source for both the brain and the body.
But when the body adapts to a low-carb diet, things can get tricky at first. The body responds to a series of changes to transition from using glucose (carbs) for energy to using ketones as fat. Blood sugar drops, causing hyptoglycemia (which is low blood sugar < 55mg/dl.1 Other bodily systems that alter electrolyte, water, and hormone levels can lead to dehydration.
Ketosis can provide a wide range of health and weight loss benefits, but the early transition period may cause some people to experience temporary unwanted side effects including the keto flu, an electrolyte imbalance, or even what’s known as the keto rash.
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What is Keto Rash?
The keto rash, better known as prurigo pigmentosa, is a rare inflammatory skin condition associated with ketosis causing red itchy rashes on the neck and upper body.2 Although there is limited research on keto rash, we do know a few things. What people are the most affected while doing a ketogenic diet? It’s twice as common in girls and women, and the average age of onset is 25.3
Prurigo pigmentosa is different from other skin lesions in its unique reticular pattern, which occurs during all stages of the condition.4
If those rectangular bumps all over your body aren’t enough of a sign, let’s look at a few more symptoms of keto rash.
Symptoms of Keto Rash
The symptoms of keto rash can look similar to dermatitis or eczema; as a result, some people may initially be misdiagnosed. Symptoms of the keto rash may include one or more of the following:
An itchy, red skin rash found on the upper back, chest, and neck typically occurring in a symmetrical pattern on both sides of the body2
Red-colored spots known as “papules,” which usually have a web-like appearance2
Dark spots left on the skin after the spots dissipate2
Prurigo pigmentosa is not a life-threatening or dangerous condition, but it can cause discomfort to those dealing with it.
Stages of Keto Rash
The keto rash consists of four main stages, including: early lesions, fully-developed lesions, resolving legions, and late lesions.5
Early lesions: Early stages consist of light pink raised skin lesions that look similar to scratch marks. These will usually occur around the stomach, chest, back, and neck. Oftentimes, people confuse this stage as a temporary rash and don’t do anything to address the symptoms.
Fully-developed lesions: The skin begins showing more distinct skin lesions, also known as papules. Sometimes these papules contain liquid or pus-filled cysts. This is typically the time when people become concerned about the condition.
Resolving lesions: The rash begins to recede and papules become crusty. The color of the legions tends to get darker.
Late lesions: Once the rash begins to go away, the spots turn darker and they form a web-like appearance. This formation of dark skin discoloration can last an extended period of time, even after the rash is gone.
The severity of the rash can vary from person to person. Anecdotal research has shown it can last days for some people while others may take months to occur.
What Causes Keto Rash?
While we’ve touched on carb-depletion as a potential reason for keto rash, the exact cause of is unknown. The rash typically appears when someone has started to enter ketosis.
Several case studies have been performed on subjects experiencing the keto rash, and most were following a low-carbohydrate diet.
A 16 year-old complained of a case in which she experienced red, pruritic vesicles on her trunk and neck. During the month prior to outbreak, she had begun a strict low-carbohydrate diet. She experienced papules on her neck, back, and clavicle areas. She also had pale brown reticular pigmentation on her front chest. She was treated with 100mg dosage of doxycycline per day, and the rash eventually subsided.6
Symptoms typically arose as a result of ketosis. Anecdotal research has shown the condition may be exacerbated by sweat that dries on the body.
Besides from dietary choices, there are also external factors which can influence the severity of keto rash including:
Other skin allergies
So, if you’re an active, outdoorsy individual, you may be susceptible.
Extremely hot weather and sweat from exercising can make the condition worse. If you are experiencing the keto rash, the good news is that there are several ways to remedy the condition or prevent it altogether.
How to Cure the Keto Rash?
The keto rash can be an unfortunate side effect of the ketogenic diet for a small number of people.
The condition is rare and uncomfortable, but not considered life threatening. Here are some ways to help you get rid of the keto rash starting with the least drastic measures.
Give it Time
This feels like some advice a father would give; akin to “walk it off.”
Some instances of keto rash may be resolved on their own by waiting for symptoms to subside. The transition to ketosis can take time for the human body to grow accustomed. Don’t panic if a rash does occur. It could go away on its own.
Although the rash can sometimes disappear on its own, don’t wait for too long. If the symptoms don’t go away after a week or two, it may be to take some additional steps to combat the skin irritation.
You’ve worked hard to get into ketosis. So before making any drastic dietary changes, let’s consider some alternatives taking. Since several external factors can influence the severity of the keto rash, try doing a few of the following things first.
Wear comfortable clothing: this may sound like a no-brainer, but try wearing comfortable, loose-fitting clothing. If you can minimize the amount of sweat on your body, you can reduce the severity of the keto rash. Tight fitted clothing that traps sweat against the skin will only serve to make the condition worse.
Shower immediately following exercise: if you regularly perform intense workouts, chances are you sweat quite a bit. After finishing your workout, try to shower immediately if possible. This will help keep pores clear and may prevent the rash from spreading.
Adjust or quit exercising temporarily: obviously regular exercise provides a number of health benefits, but if it causes severe skin conditions, consider taking a brief hiatus. Eliminate all exercises and sweat-causing activities from your routine and see if the keto rash subsides.
If none of the methods above help to resolve keto rash issues, then it's time to take some additional steps that can help combat this dreaded condition.
Eat Sufficient Nutrients
Nutrient deficiencies can play a significant role in overall skin health. When switching to a ketogenic diet, it's important to make sure you’re still getting vital nutrients in your diet.
Acute and chronic skin conditions can occur if your body is lacking in vital micronutrients such as vitamin A, vitamin B-12, or vitamin C.
A 2010 study concluded that dietary modifications to address nutritional deficiencies may help prevent recurrences of many skin conditions.7
Be sure to eat plenty of vegetables and low-carb fruits to optimize your health and well-being. If this becomes difficult, consider taking some form of multi-vitamin or supplementation to counteract any lack of nutrients in your diet.
Eliminate Inflammatory Foods
The cornerstone of keto is low-carb, high-fat foods, such as eggs, dairy, fish, and nuts. Some of these foods contain compounds that act as allergens to many individuals, which may lead to inflammation.
Allergic inflammation now afflicts roughly 25% of people in the developed world. Allergic subjects can result in chronic allergic inflammation resulting in long-term changes in the structure of organs and abnormalities in their function.8 It’s important to eliminate food allergies from your diet in order to minimize the potential chance of allergic reactions. You may also have a slight intolerance to a food that you never realized because you weren’t eating it in large quantities.
When symptoms of keto rash arise, it's important to note any dietary changes that you may have made. Eliminate potential inflammatory foods to prevent rash symptoms from worsening.
Use Anti-Inflammatory Supplementation if Needed
If the elimination of inflammatory foods still doesn’t work, try using anti-inflammatory supplementation if needed.
Meta analyses have shown certain supplements may help lessen symptoms of dermatitis. Natural therapies such as probiotics, prebiotics, and fish oil have been used to decrease the symptoms of skin irritations.9 If you’re looking for a high-quality Omega-3 fish oil, check out Kado by H.V.M.N. It contains astaxanthin, a natural anti-inflammatory.10,11,12
Reintroduce Carbohydrates into Your Diet
If the rash still isn’t going away, it may be time to add some carbs back into your diet.
If a sudden switch to a keto diet caused the rash to occur, temporarily add healthy high-quality carb sources into your diet such as sweet potatoes, yams, fruit, fortified whole grains, or carrots.
There have been several case reports of reintroducing dietary carbohydrates to help resolve skin problems.
A 43 year-old woman began experiencing symptoms of keto rash three weeks after beginning a ketogenic diet (consisting of less than 20g of carbs per day).
She quickly developed skin lesions that turned into papules. Exercising made her condition worsen. All attempts to combat the keto rash were unsuccessful until she resumed a higher carbohydrate diet. After adding carbs back into her diet the keto rash never occurred again.2
An 18 year-old Japanese man began a ketogenic diet and started developing symptoms of the keto rash after nine days. Carbohydrate intake was raised from 16g per day to 90g per day and symptoms subsided and remained gone even after an 8 month follow-up.2
Both cases were resolved by an increase in dietary carbohydrates. Everyone is different, so adhering to a strict, < 50g of carbs per day ketogenic diet might not be best for your needs. Try adjusting macronutrient ratios and incorporating more healthy carbohydrates into the diet.
Cyclical Ketogenic Diet
Although people tend to think of keto as an all-or-nothing diet strategy, the truth is another option exists.
The cyclical ketogenic diet is an alternative form of keto that allows you to stay in ketosis most of the time while consuming carbs one to two days per week.
Most people eat keto five to six days per week and consume controlled amounts of complex carbs the remaining days. This doesn’t mean you go all out and stuff your face with pizza.
On cyclical keto, your “carbing-up” days will allow you to eat healthy carbohydrate options in moderation.
Certain people, such as strength athletes and bodybuilders, may perform better with some carbohydrates because they’re a fast-burning fuel best reserved for high-intensity exercise.13 Just schedule carb-up days around heavy workouts for optimal use of glucose stores.
Utilizing this strategy, you may be able to enjoy the benefits of keto while minimizing unwelcome side effects such as the keto rash.
Practice Skin Care
Your skin should be nourished and properly cared for as much as the rest of your body—especially if you are prone to certain skin conditions.
Use room temperature water to wash your body and clean with gentle, all-natural soaps. Using extremely hot water can cause the rash to become inflamed and worsen over time. Certain soaps can also cause the skin to be irritated.
You should also keep skin moisturized at all times to protect against sun damage and harmful UV rays. People with especially sensitive skin should take care to avoid external irritants.
Use Medication if Necessary
Dietary and lifestyle changes may not clear up skin conditions for all people.
If you have tried all of the steps listed above, a doctor may prescribe anti-inflammatory medications such as minocycline or doxycycline to clear up your skin. These antibiotics can be useful for clearing up rashes if needed.
It's important to note that only a doctor can determine if medication is right for you.
Prevention and Care
The keto rash is rare side effect sometimes associated with the ketogenic diet. Although it is uncommon, you should consider taking a few extra steps to prevent it.
Each and every person’s body reacts differently to the keto diet. As with any diet, its best to make slow gradual adjustments rather than jumping right into full keto. Slowly cut carbohydrates from your diet until you’re able to taper them out completely.
As you begin your keto journey, pay close attention to potential issues that may arise. If you begin to notice symptoms of keto flu or keto rash, temporarily increase carb intake to prevent symptoms from getting worse. There are also other measures you can take, including: avoiding inflammatory foods, not wearing tight clothing, and ensuring proper balance of micronutrients.
If home remedies fail to improve your condition, see your doctor, who may be able to provide you the tools necessary to help you alleviate keto rash.
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Desimone ME, Weinstock RS. Non-Diabetic Hypoglycemia. [Updated 2017 Sep 23]. In: De Groot LJ, Chrousos G, Dungan K, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK355894/
Lee SJ, Bai SK, Lee KS, et al. Astaxanthin inhibits nitric oxide production and inflammatory gene expression by suppressing I(kappa)B kinase-dependent NF-kappaB activation. Mol Cells. 2003;16(1):97-105.
Nakano M, Onodera A, Saito E, et al. Effect of astaxanthin in combination with alpha-tocopherol or ascorbic acid against oxidative damage in diabetic ODS rats. J Nutr Sci Vitaminol. 2008;54(4):329-34.