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. 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 hyperpigmentation2, meaning the patches darken beyond the natural skin tone. One study from Malaysia analyzed adults with prurigo pigmentosa and found five of the nine participants were following a keto diet4. 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 condition5. 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 PP6, 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. 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. 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. “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.