What Is Keto Rash? Experts Explain Causes, Treatment & Prevention
The ketogenic diet (keto, for short) is a popular low-carb, high-fat diet with a range of potential health benefits. The eating plan has been shown to help balance blood sugar, lower insulin levels, and help manage weight. Along with the reported benefits, however, keto can also lead to unwanted side effects.
You may have heard about keto crotch and keto breath, but what about keto rash? To better understand the skin condition, mbg consulted registered dietitians and integrative medicine doctors to find out how the diet can interfere with skin health.
What is keto rash?
Keto rash is a colloquial term used to describe prurigo pigmentosa (PP), or Nagashima disease. The condition is a type of dermatitis (aka inflammation of the skin), which typically affects the upper part of the body, says dietitian and keto educator Priscilla Blevins, M.S., R.D., L.D.
Symptoms of the disorder include red bumps or patches on the skin, most commonly on the stomach, chest, or back. Following the inflammatory phase, some people experience skin hyperpigmentation, meaning the patches darken beyond the natural skin tone.
What causes a keto rash?
"Although this condition is traditionally considered rare, prurigo pigmentosa reports are emerging more with the growing popularity and implementation of the ketogenic diet," registered dietitian Molly Knudsen, M.S., RDN, tells mbg.
One study from Malaysia analyzed adults with prurigo pigmentosa and found five of the nine participants were following a keto diet. A slightly older study from 2011 had similar results, in which six of the 16 participants who followed a keto diet later developed the skin condition.
The exact cause of keto rash is unknown but tends to be more common in women, says Sara Gottfried, M.D., integrative medicine doctor and New York Times bestselling author.
According to research, certain irritants like sweating, clothing friction, rubbing, or contact dermatitis can lead to PP, as well as metabolic associations from diabetes mellitus, fasting, dieting, and excess levels of ketones in the body.
"This is a rare occurrence but can happen when one initially goes keto," Blevins says. "If it happens, it will typically occur within the first two weeks of starting the ketogenic diet," she adds.
What can you do to treat keto rash?
This skin inflammation may be the body's way of saying it needs more carbohydrates. "In nutritional ketosis, increasing carbohydrate intake improves the rash according to anecdotal evidence," Gottfried says.
If that's the case, Knudsen says following a low-carb diet, carb-cycling, or not restricting carbs at all may be better approaches for some individuals.
If continuing to follow a keto diet is necessary for medical reasons, such as diabetes or epilepsy, Knudsen recommends reaching out to a doctor or medical care team to find the best treatment option. "Antibiotics may be beneficial or necessary to fully eliminate the rash," she explains.
How to prevent keto rash.
While there's no real way to prevent keto rash, there may be some ways to lower the risks. Rather than eliminating carbs all at once, modulating carbohydrate intake may be easier on the body, Gottfried says.
Reaching out to a doctor or a registered dietitian could also be useful, as they can provide tips for safely implementing the diet and help monitor for symptoms during the transition.
Since there's no clear cause for keto rash, anyone transitioning to a keto diet may be at risk.
"If you are following a ketogenic diet, keep an eye out for any unusual changes in skin appearance, especially on the upper body, and seek medical attention as soon as you notice a rash forming," Knudsen says. Though it may be unpleasant, keto rash is treatable.
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