RELATED: What to Eat and Avoid on the Ketogenic Diet

The Effects of the Keto Diet on Skin Are Unclear, but There Are Some Known Risks

A keto diet is a high-fat, moderate-protein, and very-low-carb eating plan. This shift of macronutrients drives your body into ketosis, or a state where you burn fat as your main energy source, rather than its preferred fuel, carbohydrates. It’s a profound metabolic shift. With regards to treating eczema, it’s important to point out that there’s a distinct lack of medical literature proving the keto diet is helpful. Yet clinicians have an idea of how this diet approach may affect your skin. “In the world of dermatology, keto is actually problematic for the skin. There are multiple reports that show it causes dermatitis,” meaning inflammation of the skin, says Vivian Shi, MD, an assistant professor of medicine in dermatology at the University of Arizona in Tucson and director of the Eczema and Skin Barrier Clinic. For instance, a case study published in May 2018 in the Hawai’i Journal of Medicine & Public Health looked at two patients on the keto diet who developed a rare type of inflammatory skin rash called prurigo pigmentosa, which they treated by changing their diet to consume more carbs. A June 2019 review in JAAD Case Reports outlines three case studies that suggest the skin condition is associated with starting the keto diet. Another potential downside: nutrient deficiencies. “Your skin is one of the most metabolically active organs in the body, and it’s constantly requiring nutrients,” says Dr. Shi. People who jump to a keto diet for weight loss are usually pleasantly surprised by how quickly they shed pounds, and that’s largely due to water weight from severe carbohydrate restriction. This purging of body water can also worsen skin dryness and itchiness for those with eczema, she says. One example is pellagra, a disease that results from vitamin B3 (niacin) deficiencies and often affects underserved countries where malnourishment is a problem, says Shi. Skin symptoms including a scaly rash is one sign of pellagra, notes MedlinePlus. When it comes to prurigo pigmentosa, Shi says, it’s less common in the Western world and seen more often in Asia. Yet blogs such as Ruled.Me have described this as the “keto rash,” so there are some signs that more people are developing it. RELATED: Why Keto Can Make You Constipated or Give You Diarrhea — and How to Deal The keto rash is on top of the normal symptoms of what’s commonly referred to as the “keto flu,” which happens as your body adjusts to ketosis. Effects include nausea, headaches, and fatigue. Harvard Medical School points out that sleeping trouble can be another effect of the keto flu, and a review published in May 2016 in the International Journal of Molecular Sciences shows that sleep problems can exacerbate certain skin conditions. What you eat also has an impact on your gut microbiome, or the colony of bacteria in your gut that affects every system of your body, from digestive health to immunity. “The keto diet is probably altering the gut microbiome in a way to cause dermatitis,” says Shi. “We know that an altered microbiome leads to skin conditions, but exactly how isn’t known,” she says. For instance, research shows that an imbalanced gut microbiome, or lack of diversity in bacteria in the gut, may be linked to an increase in the risk of skin conditions like eczema, per a review published in April 2019 in the Journal of Clinical Medicine. What’s more, while you may be eating bacon, cheese, and avocado to stay in ketosis — and this state is likely keeping you feeling full — exhausting carb stores “is essentially a starvation diet, and starvation is a type of stress that can flare eczema,” says Shi. RELATED: Is the Ketogenic Diet Good or Bad for Your Skin?

Could Keto, as a Form of the Elimination Diet, Offer Advantages for Eczema?

An elimination diet of any form isn’t a cure for eczema, according to the National Eczema Association. Yet for some people with this skin condition, food sensitivities may contribute to flare-ups, says Robin Foroutan, MS, RD, an integrative dietitian at the Morrison Center in New York City and spokesperson for the Academy of Nutrition and Dietetics. Some of the foods that keto eliminates, like wheat, most dairy, added sugar, and citrus, could potentially help improve skin if you have a sensitivity to those foods. But, she says, some of the foods allowed on keto, such as eggs or tomatoes, may also exacerbate problems. The link between food allergies and eczema is controversial. But infants and young children with moderate to severe eczema are more likely to have the conditions together. When it happens, you’ll notice a flare six hours up to two days after eating the food, according to a review published in March 2014 in The Journal of Clinical and Aesthetic Dermatology. That potentially delayed response can make pinpointing the offender particularly tough (and require a dermatologist’s diagnosis and care to do so). The authors of the aforementioned review note that while it’s unknown how many children with eczema are affected, this phenomenon is uncommon in adults. People who are best suited for food allergy testing, which can include an elimination diet, are children younger than 5 who have moderate to severe eczema and where standard treatment hasn’t helped. RELATED: Should You Try an Elimination Diet to Treat Eczema?  It’s no guarantee that minding potential food sensitivities will soothe your skin. “Because the research on this is dicey, even some people with severe cases who avoid food triggers don’t see a difference,” says Angela J. Lamb, MD, an associate professor of dermatology at the Ichan School of Medicine at Mount Sinai in New York City. “Still, anecdotally, I have patients who say their skin does get better and they swear by food sensitivity testing,” says Dr. Lamb. If you’re an adult and interested in an elimination diet, it’s best to work with a registered dietitian and your dermatologist. But you can do so safely on your own by eliminating the aforementioned foods for a month and slowly adding each back in to see if your skin reacts, says Foroutan. But ultimately, know that a keto diet in its traditional form is not a cure for eczema. While you may be removing big sources of carbs from your diet (like wheat and added sugar), you won’t be counting or specifically limiting sources of carbs from other places (like fruit and vegetables). RELATED: The Connection Between Eczema and Diet

What to Eat for Better Skin and Potentially Improved Eczema

When it comes to the role diet plays in skin health, Lamb says that what we do know is that what you eat may be linked to skin conditions like acne. Specifically, diets higher in glycemic load (a measure of both the quality and quantity of carbohydrates, per the Glycemic Index Foundation) and dairy may be associated with worsening acne, per an April 2016 review in Advances in Dermatology and Allergology. Inflammation plays a role in the development of both acne and eczema. As the National Eczema Association points out, when the immune system is triggered, it produces inflammation, which gives rise to red, itchy, and scaley flare-ups. Likewise, there’s evidence of increased levels of inflammatory cells in skin during the early stages of acne. Taking a cue from that research, avoiding low-fat dairy and foods high on the glycemic index (white bread, white potatoes, processed snack foods, high-sugar foods) may be helpful in clearing skin, says Lamb. Above all else, an anti-inflammatory diet is a good first step to see if it makes a notable difference in flare-ups, says Foroutan. That can take many different forms — from a vegetarian to traditional (but well-planned) low-carb diet — but you’d be focusing on whole foods in a Mediterranean diet. The National Psoriasis Foundation says an anti-inflammatory diet limits fatty red meats, refined sugar, processed foods, and dairy, and emphasizes fatty fish, nuts, seeds, olive oil, and fruit and vegetables. (While eczema and psoriasis are two different conditions, inflammation is a common thread that underlies both and triggers symptoms.) If you’re having trouble managing eczema, see your dermatologist. “Most of my patients try everything before they get to me, such as using moisturizer, drinking more water, and avoiding food triggers,” says Lamb. Effectively treating eczema goes beyond your diet; your dermatologist may prescribe cortisone or noncortisone topical creams, light therapy, or consider if you’re a candidate for the new injectable FDA-approved medication Dupixent (dupilumab). RELATED: How Stress Can Trigger Eczema and How to Avoid a Flare-Up

The Bottom Line on Following Keto to Treat Eczema

Keto can’t cure eczema. In fact, because this eating plan may cause a red, itchy rash itself, it may worsen eczema symptoms. On the other hand, a diet that focuses on eliminating potential triggers for your flares may help. The best way to approach your eczema treatment is by working with your healthcare team to come up with an individualized game plan. “A specific diet definitely wouldn’t cure someone’s eczema — nor is there any cure we know of right now,” says Shi.