Do patients come to you with eczema that conventional therapy fails to treat? While eczema is a multifactorial disease, addressing the underlying causes offers great potential for achieving remission. Read on to learn how to treat eczema with a functional approach.
The prevalence of eczema and other forms of atopic dermatitis has increased dramatically in the last decade (1). Atopic dermatitis now affects up to 20 percent of children and up to 3 percent of adults (2) and presents a significant burden on the healthcare system and the patient’s quality of life. Conventional therapy for eczema includes topical steroidal creams, corticosteroids, immunomodulators, or antihistamines, all of which require continued use and do not address the underlying cause of disease.
Enter functional medicine. By identifying underlying pathologies and providing the body with the nutrients it needs, eczema can truly be healed from the inside out. In this article, I’ll discuss the most important considerations for patients with eczema.
Remove Foods That Trigger an Immune Response
Conventional medicine often discounts the connection between skin health and diet. Yet food choices strongly influence the health of our skin.
Food Intolerance Testing
Many patients with eczema produce antibodies to a wide variety of foods (3). Food sensitivity panels, such as those from Cyrex, can allow us to see which foods might be triggering an inflammatory immune response in a patient. The most useful tests for those with eczema might include:
- Cyrex Array 3: Wheat/gluten proteome reactivity and autoimmunity
- Cyrex Array 4: Gluten-associated cross-reactive foods and food sensitivity
- Cyrex Array 10: Multiple food immune reactivity screen
Note that patients must have consumed the food recently for the test results to be accurate.
The Paleo Autoimmune Protocol
While eczema is not officially recognized as an autoimmune disease, it shares many of the same characteristics (4). Because of this, many patients with eczema benefit from 30, or ideally 60, days on the Paleo Autoimmune Protocol (AIP). Like on a basic Paleo diet, the patient would remove grains and dairy, but also eggs, nightshades, and possibly nuts and seeds. These are foods that are thought to be likely to cause intestinal inflammation and/or cross-reactivity with tissues. While there is no peer-reviewed evidence to support the Paleo Autoimmune Protocol, anecdotal experience from myself and other practitioners has shown that some patients are indeed sensitive to some of these foods. After 30 to 60 days, the patient can add foods back in one at a time and observe their symptoms to see what they are most sensitive to. Other patients may resolve eczema just from adopting a Paleo diet and removing grains, dairy, and refined seed oils.
Got eczema? Stop treating the symptoms and get to the root cause.
Increase Intake of Nutrients That Promote Skin Health
Vitamins, minerals, and other dietary nutrients significantly impact skin growth and immunity (5). There are several nutrients that are particularly important for skin health and optimal immune function.
Synthetic retinoids have been used for inflammatory skin conditions since the 1980s (6). They promote differentiation and cell turnover and modulate dermal growth factors. A lack of vitamin A causes hyper-keratinization and suppressed mucus secretion (7). Rough, dry skin is a common sign of vitamin A deficiency and characteristic of eczema. While some carotenoids like beta carotene can be converted to retinol (8), it’s best to ensure adequate intake by consuming preformed retinol from animal sources, such as liver, kidney, pastured egg yolks (if tolerated), and extra-virgin cod liver oil. About four to six ounces of beef liver or one teaspoon of extra-virgin cod liver oil per day should provide adequate vitamin A.
Zinc plays a role in the skin’s immune function, protein synthesis, wound healing, DNA synthesis, and cell division (9, 10, 11). It protects against ultraviolet radiation and has anti-inflammatory effects. It also interacts with vitamin A as a component of retinol-binding protein (RBP) and significantly increases the level of vitamin A in the blood (12). Zinc is more bioavailable in animal foods than in plant foods, where it is often bound to phytic acid (13). The best food sources are organ meats like kidney and liver, red muscle meats like beef and lamb, and shellfish. Plant foods like pumpkin seeds and nuts have high zinc content, but the zinc in these foods is less bioavailable. Soaking and sprouting nuts and seeds can help liberate some of the bound zinc (14), so they can still be good sources if prepared properly and well tolerated.
Vitamin C is an antioxidant that is crucial for the production and regulation of collagen (15). Collagen maintains the extracellular stability of the skin. Studies show that diets that are high in vitamin C are associated with healthier skin appearance (16). Vitamin C also reduces dry skin by reducing transepidermal water loss and is important for wound healing and scar tissue repair (17). The highest food sources of vitamin C are bell peppers, guava, dark leafy greens, broccoli, Brussels sprouts, citrus fruits, and strawberries. Consuming a wide variety of plant foods regularly is the best way to get adequate vitamin C in the diet. Vitamin C is heat sensitive, so a mix of raw and lightly cooked plant foods is best for optimal vitamin C intake.
Omega-3 fatty acids are anti-inflammatory and play an important role in skin health. They have been shown to decrease skin inflammation and reduce redness, itching, and scaling of the skin (18). Supplementation of omega-3s has also been shown to improve atopic dermatitis (19). The best source of omega-3 fats, including both EPA and DHA, is cold-water fatty fish. I recommend about 12 to 16 ounces of these types of fish per week. These include sardines, salmon, mackerel, trout, anchovies, black cod, and shellfish.
Biotin is an essential cofactor for enzymes that regulate fatty acid metabolism (20). Fatty acids in the skin help protect cells against damage and water loss, and inadequate biotin intake causes dermatitis (21). True biotin deficiency is rare unless a patient is consuming raw egg whites. Avidin, a protein in raw egg whites, binds with biotin and prevents its absorption in the gut (22). Still, some patients may need additional biotin in order to get a therapeutic effect, so foods like egg yolks (if tolerated), liver, Swiss chard, and romaine lettuce are good sources. Biotin is also produced by beneficial bacteria in the gut, so if biotin is low, restoring a healthy gut microbiota is also important.
Selenium has decreased in its availability due to degradation of soil quality (23). Intestinal inflammation can also result in selenium deficiency due to malabsorption (24). Selenium is a component of selenoenzymes that allow glutathione to function (25). It is best to get selenium from the diet because some studies show that long-term supplementation with even as little as 200 micrograms per day of selenium when the patient already has adequate selenium levels can cause an increase in prostate cancer risk in men (26). The best sources of dietary selenium are organ meats, seafood, beef, turkey, and lamb. Brazil nuts are also incredibly potent sources of selenium if the patient tolerates nuts—just two Brazil nuts can provide around 200 micrograms of selenium.
Silica interacts with glycosaminoglycans, or GAGs, to form the building blocks of skin tissue (27). A silica-deficient diet has been shown to cause poorly formed connective tissue, including collagen (28). The impact of silica on collagen formation and GAGs may lead to increased skin firmness and elasticity. The best food sources of silica are leeks, strawberries, cucumber, mango, celery, asparagus, and rhubarb. It’s also found in certain brands of water, like Fiji water, or trace mineral drops, which can be added to plain drinking water.
Niacin is also known as vitamin B3. Deficiency of niacin can result in pellagra, the symptoms of which include dermatitis (29). Low intake of niacin is uncommon, but certain conditions, like celiac disease, SIBO, or inflammatory bowel disease, can impair niacin absorption or increase the need for niacin (30). Food sources of niacin include meat, poultry, tuna, salmon, seeds, green leafy vegetables, coffee, and tea. The liver can also convert tryptophan, a common amino acid, to niacin. Some patients may benefit from supplementation, but be aware that excessive niacin can cause significant side effects, such as flushing (31).
Vitamin K2 prevents calcification of the skin’s elastin, a protein that gives skin its youthful, springy quality (32). K2 has been shown to be important for the proper functioning of vitamin A- and vitamin D-dependent proteins. Food sources of vitamin K2 include high-fat, grass-fed dairy, especially cheese and ghee, as well as egg yolks, liver, natto, and sauerkraut. Be sure that the source they choose is well tolerated by the patient, since many patients with eczema are sensitive to dairy, eggs, and soy.
A large proportion of the Western population consumes inadequate amounts of sulfur. Sulfur is necessary for both collagen and glutathione synthesis (33). Glutathione prevents oxidative damage to cells and regulates the production of prostaglandins, reducing inflammation (34). Sulfur-containing amino acids are found in meat, poultry, fish, garlic, onion, Brussels sprouts, asparagus, kale, broccoli, and cabbage. Fermentation makes sulfur more bioavailable, so fermented cruciferous vegetables are particularly good sources of sulfur.
Vitamin E is secreted on the skin’s surface through the sebum. It has potent anti-inflammatory effects, defending the skin against free radicals that cause skin damage (35). It has synergistic effects with selenium to increase glutathione levels; is involved in immune function, cell signaling, and gene expression; and suppresses the formation of inflammatory arachidonic acid (36, 37, 38). The majority of Americans get vitamin E from polyunsaturated vegetable oils like soybean, canola, and corn oil. The best sources in a Paleo-type diet are spinach, turnip greens, Swiss chard, bell peppers (if tolerated), asparagus, collards, kale, and broccoli. Olive oil and avocado oil contain vitamin E as well and are great oils to cook with. Supplementation with vitamin E is not recommended in most cases because studies have shown that longer-term supplementation with vitamin E may actually increase the risk of death from cancer and heart disease (26, 39).
Also known as B5, pantothenic acid supports wound healing and growth and differentiation of keratinocytes. When applied topically, it helps to regenerate skin cells and connective tissue and significantly increases glutathione levels in cells, protecting against oxidative damage (40). B5 is found in a variety of foods. The richest sources include organ meats like liver and kidney; egg yolks; and broccoli. It’s also in fish, shellfish, dairy products, chicken, mushrooms, avocado, and sweet potatoes. Be aware that high heat processing reduces B5 levels in foods by up to 74 percent (41), so it’s important to eat a mix of raw and lightly cooked fresh foods to obtain adequate B5.
Vitamin D has been shown to promote T regulatory cell function and have multiple positive effects on immune balance (42). In a patient with an autoimmune disease or atopic dermatitis, I typically recommend aiming for a serum 25(OH)D range of 40 to 60 ng/mL. Achieving a vitamin D level higher than 60 ng/mL is not necessary and as I’ve written before, may be detrimental. Food sources of vitamin D include cold-water fatty fish, cod liver oil, and pastured chicken and duck eggs (if tolerated). Of course, sunlight is another important source, but that depends on the latitude that the patient lives at, the time of year, time of day, the amount of time they are spending in the sun, and some individual health factors. Moderate doses of ultraviolet rays have been shown to improve the healing of eczematic lesions (43).
Address Gut Pathologies and Promote a Healthy Gut Microbiota
The gut–skin axis has been studied as far back as the 1930s. The gut microbiota influences systemic inflammation, oxidative stress, glycemic control, and tissue lipid content. Intestinal permeability can lead to skin conditions like eczema. Stress and gut inflammation can also cause leaky skin, similar to leaky gut, which is an impaired epidermal barrier characterized by decreased antimicrobial peptides, increased chance of infection, and inflammation. I’ve written about this before on my blog.
Addressing gut pathologies, such as H. pylori, SIBO, parasites, and intestinal permeability, is an important first step to treating eczema. You also need to rebuild a healthy gut microbiota by eating a nutrient-dense diet that includes probiotics and prebiotics.
Probiotics have been shown to improve eczema, reduce inflammation, and decrease lipopolysaccharide in the blood (44, 45). The best food sources of probiotics are fermented foods like sauerkraut, kimchi, yogurt, kefir, and kombucha. Oral probiotics can be taken as supplements, but use caution if the patient has SIBO or other existing gut issues that may need to be treated first. Soil-based organisms or transient commensals would be the exception, since these are usually used safely even when SIBO is present. My favorite brands are Primal Probiotics and MegaSporeBiotic.
In addition to probiotics, you should also encourage your patients to focus on fermentable fibers. These are non-digestible carbohydrates that feed the beneficial bacteria that already reside in the gut. These include onions, leeks, garlic, Jerusalem artichokes, and starchy vegetables. Prebiotics have been shown to significantly improve atopic dermatitis severity in children (46).
Assess HPA Function and Manage Stress
Stress management is an incredibly important, and often overlooked, component of improving skin health. Yet there are now several highly cited articles that discuss the gut–brain–skin axis (47, 48, 49). Stress has been shown to impair wound healing (50), and atopic dermatitis patients often have low cortisol, indicating a dysregulated hypothalamic–pituitary–adrenal (HPA) axis (51). Some studies have even suggested that the use of potent topical glucocorticoids may play a role in HPA suppression in atopic dermatitis patients (52).
Encourage patients with eczema to practice stress management techniques, entrain circadian rhythms, and regulate blood sugar. HPA-D testing may also be beneficial for some patients to determine if supplementation might be helpful.
Address Heavy Metal Toxicity
Many individuals in the modern world have undiagnosed heavy metal toxicity, and a high percentage of patients who have chronic disease are dealing with it on some level. The skin is a primary toxin elimination organ, so it’s no wonder that atopic dermatitis is associated with heavy metal exposure (53).
If you suspect heavy metal toxicity in eczema patients, you may want to look into heavy metal testing. Be sure to support liver function and detoxification as you begin treatment, since mobilization of heavy metals can cause eczema flares if they are not efficiently removed from the body.
Avoid Topical Irritants
Some individuals suffering from eczema may be suffering from contact eczema, which is produced from an irritation to a particular chemical or substance. For individuals with atopic eczema, environmental toxins or detergents in common cosmetics can exacerbate skin inflammation and increase transepidermal water loss (54). Avoiding toxins on the skin and cultivating a healthy skin ecosystem are important considerations in treating atopic dermatitis.
While synthetic moisturizers might make a patient more comfortable in the short term, they often have harmful ingredients that cause inflammation in the skin and only serve to dry it out in the long term. Instead, encourage patients to try natural alternatives such as coconut oil, which has been shown to improve wound healing and reduce inflammation (55).
Many patients with eczema may also have what is known as “histamine intolerance.” In some cases, histamine intolerance is a result of mast cell activation disorder. However, symptoms of histamine intolerance can also be caused by excess histamine production, diamine oxidase (DAO) enzyme deficiency, histamine n-methyltransferase (HNMT) mutation, or poor methylation in the liver (56).
Supporting gut health, resolving infections, and improving liver methylation capacity will all help improve histamine intolerance, and by extension, eczema symptoms. A low-histamine diet may also help during the healing process. Check out this podcast transcript for a full list of high-histamine foods that patients with histamine intolerance should limit or avoid. You can also supplement with antihistamines. For example, the polyphenol quercetin has been shown to stabilize mast cells and ameliorate symptoms of contact dermatitis (57).
Like many diseases, the etiology of eczema is multifactorial. However, I’ve seen many patients achieve complete resolution with the proper diet, lifestyle, and supplemental support. Here’s a quick recap of the most important considerations in treating eczema the functional way:
- Identify food intolerances. Many patients with eczema have underlying food intolerances and therefore can benefit greatly from food intolerance testing and the Paleo Autoimmune Protocol.
- Nourish the body with nutrients that support skin health and optimal immune function, whether in food or supplemental form.
- Support gut health with probiotic and prebiotic foods.
- Address heavy metal toxicity.
- Emphasize stress management and encourage patients to find a technique to practice daily.
- Recommend strict avoidance of detergents and other topical irritants that can cause skin barrier permeability and exacerbate inflammation.
- Consider the role of histamine.