Keto Rash: Symptoms, Stages, Causes, Treatment & Prevention

Written by Lynn Hetzler
on January 16, 2020

Questions Answered:
  • What is keto rash?
  • What are the treatments for keto rash?
  • How to avoid keto rash?
  • What does keto rash look like?


The ketogenic diet, also known as the keto diet, is a popular approach to weight loss. The keto diet is a low-carb, high-fat diet that causes the body to burn fat instead of carbohydrates for energy. This leads to increased fat burning and weight loss. Most people tolerate the keto diet well, but for some people, the ketogenic diet can cause a rash.

What Is Keto Rash?

A keto diet involves maintaining a state of ketosis, in which the body burns fat instead of carbohydrates for energy. During the process of burning fat, the liver produces a type of acids known as ketones. The liver releases ketones into the bloodstream, where muscles and other tissues can absorb the ketones and use them as energy. The ketogenic diet keeps the body in a state of ketosis. For someone without diabetes, the presence of ketones is harmless, but it can cause some people to develop a keto rash.

Keto Rash Symptoms

Doctors refer to keto rash as “prurigo pigmentosa.” Japanese dermatologist Masaji Nagashima first described prurigo pigmentosa in 1971. Full-blown prurigo pigmentosa is a rare condition, affecting only about 300 people, but many more people experience a milder form of the rash as they enter ketosis. Researchers think it may be more widespread because doctors outside of Japan are not aware of it.

Keto rash is different from keto flu, which causes flu-like symptoms as the body switches from burning carbohydrates to burning fat for energy. Symptoms of keto flu generally develop 24 to 48 hours into ketosis, and can include brain fog, headache, muscle soreness, insomnia, irritability, inability to focus and sugar cravings.

Symptoms of Keto Rash

The keto rash is a rare form of dermatitis. It is different from other rashes in that it causes red spots or bumps, known as papules, which take on web-like appearance patterns across the skin. The rash leaves a dark brown pattern on the skin once the spots disappear.

Keto rashes typically appear on the upper body, particularly on the upper back, chest, and abdomen. It can also develop on the neck, arms, and legs. The rash is usually symmetrical, which means it appears on both sides of the body.

Itching often accompanies keto rash. The itching can be fairly intense, and can interrupt sleep. Itching tends to be worse with exercise and sweating.

Stages of Keto Rash

Keto rash develops in four stages. The first stage appears as light pink raised skin lesions, known as urticarial papuloplaques. The lesions look like scratch marks or a temporary rash.

During the second stage, the lesions become fully developed. The lesions, known as papules, are more aggressive. The papules sometimes involve fluid-filled cysts, known as papulovesicles. In severe cases, the papules become papulopustules, which are lesions filled with pus.

At the third stage, these lesions start to resolve over time. The lesions turn scaly, crusty and darker in color.


The fourth and final stage is characterized by a web-like appearance, consisting of dark spots that are larger than freckles. This phenomenon, known as reticulated hyperpigmentation, tends to remain long after the rash heals.

People recover from keto rash at different rates. For some, the rash disappears in a couple of weeks. For others, it may take several months. The last two stages seem to last the longest for most people who develop keto rash.

For many, the rash resolves without the need for treatment, even as they continue the keto diet. Other people may develop keto rash every time they go into ketosis.

Causes of Keto Rash

Medical professionals have not yet determined why the keto diet causes inflammation and are still working to determine the underlying cause of the skin condition. Researchers have theories as to why some people may develop a rash as their bodies go into ketosis. Some think may be associated with the type of ketone known as acetone, for example. When excreted through the skin as sweat, acetone can irritate the skin.

Others think that the ketones cause inflammation, which can trigger rashes. Underlying autoimmune conditions may cause flare-ups associated with prurigo pigmentosa, as can imbalances in gut bacteria.

Several conditions, especially certain autoimmune diseases, seem to be associated with keto rashes. These conditions include:

Still’s disease – an inflammatory disease that causes high fevers, joint pain and a salmon-colored rash

Sjögren’s syndrome – an autoimmune disease that causes the body to attack itself, causing a dry mouth and dry eyes

H. pylori infection – Helicobacter pylori (H. pylori) is a type of bacteria that grows in the digestive tract and can attack the stomach lining to cause stomach inflammation and ulcers; more than half the world’s population is infected with H. pylori.

External factors can aggravate a keto rash. These factors include sunlight, excessive heat, sweating, skin friction, skin trauma, and allergens.

Treatment for Keto Rash

Reintroduce carbohydrates

Since keto rash is the result of being in a state of ketosis, getting out of ketosis can help reduce keto rash. Research shows that reintroducing carbohydrates back into the diet can significantly improve symptoms of keto rash. Those who are not ready to give up the keto diet completely may opt for a moderately low-carb diet.

Correct nutritional deficiencies

Eating overly restrictive diets can lead to nutrient deficiencies, which may play a role in inflammatory skin conditions, including keto rash. Specifically, vitamin A, vitamin B12, and vitamin C deficiencies are associated with chronic and acute skin conditions.

While the keto diet restricts the consumption of fruits and vegetables, eating a wide variety of colorful fruits and vegetables when allowed can help correct deficiencies and reduce keto rash.

Eliminate food allergens

Eggs, dairy, fish, nuts and seeds play important roles in the keto diet, but they are also common food allergens, which mean they can cause allergic reactions in some people. Food allergies can cause inflammation that leads to rash symptoms. Anyone with suspected food allergies should consider avoiding these foods while on a keto diet.

Eat anti-inflammatory foods

Eating certain anti-inflammatory foods and spices can calm the rash and boost healing. More than 6,000 scientific articles published within the last 20 years show that turmeric has anti-inflammatory benefits, as well as anti-bacterial, anti-viral, anti-fungal, and anti-cancer activities. More than 65 articles show curcumin is beneficial for autoimmune conditions. Adding a dash of pepper to curcumin seems to boost its anti-inflammatory benefits. Ginger root has broad anti-inflammatory effects.  

Salmon and other fatty fish contain inflammation-fighting omega 3 fatty acids. Macadamia nuts contain monounsaturated fat and magnesium, both of which can decrease inflammation. Walnuts contain both magnesium and omega 3 fatty acids

Take anti-inflammatory supplements

Some dietary supplements can help the body fight inflammatory conditions. These inflammation-fighting supplements include beneficial bacteria known as probiotics, prebiotics that nourish probiotics, vitamin D, and fish oil supplements. A 2014 review of research literature found that evening primrose supplements could help alleviate symptoms of dermatitis.

Improved skin care

Good skin care is always important, but a healthy skin care routine is particularly helpful for those who have inflammatory skin conditions. The National Eczema Association suggests using lukewarm water for showering and bathing, and using only gentle soaps and cleansers. Keeping skin moisturized and protected from hot sun and cold wind can help reduce skin irritation.

Shower after exercise

Showering can remove some of the sweat and acetones before they can irritate the skin or aggravate an existing rash.

Avoid irritants

Friction, heat, and sweat can irritate skin. Wear loose-fitting, breathable clothing, and opt for soft materials instead of itchy wool. Avoid wearing perfumes and scented products. Do not engage in sweat-inducing exercise until skin can heal. Avoiding stressful situations can also help.

Eat probiotic-rich foods

Consume foods that feed the beneficial bacteria in the gut. A small serving of fermented cabbage, also known as kimchi, contains beneficial bacteria and enzymes that support proper digestion and healthy colonies of probiotics.

Talk to the doctor

A visit to the doctor may be in order if home treatments fail to resolve the rash. A practitioner can determine if the rash is the result of the keto diet or something else. A doctor can also perform a blood test to check for diabetes.

In some cases, a clinician may prescribe antibiotics to treat any infection associated with keto rash. Antibiotics, such as tetracycline and erythromycin, can effectively reduce symptoms of prurigo pigmentosa. Dapsone, a sulphone antibiotic that treats leprosy, may also work.

Preventing Keto Rash

It is possible to prevent keto rash and reduce its symptoms through dietary and lifestyle changes, such as:

Slowly lowering carbohydrate consumption rather than dropping carb intake suddenly

Tapering carbohydrates can give the body time to acclimate to the change in diet.

Taking multivitamin and mineral supplements at the beginning of a keto diet

Nutritional supplements can reduce the risk of rash as the body enters ketosis.

Consult with a doctor or dietician

Medical professionals can help dieters transition into ketosis safely.

For more information on keto rash, consult with a dietician or doctor who is familiar with the ketogenic diet and prurigo pigmentosa as it relates to ketosis.

Images of keto rash:




Author: Lynn Hetzler

Published: Jan. 16, 2020

Lynn Hetzler has been a leading medical and nutrition writer for more than 20 years. She regularly publishes content for doctors and other medical professionals at Multibriefs, NursesUSA, and other high profile industry publications.

Written by Lynn Hetzler

Published: January 16, 2020