Eczema, also called atopic dermatitis, is a chronic skin condition associated with irritation, inflammation, and itching. It is characterized by skin that is dry, thickened, and scaling. It most commonly occurs in the antecubital and popliteal flexures (in front of the elbow and in the thigh/groin area), as well as on the hands and feet. Atopic dermatitis has an allergic or immunologic basis, as compared to contact dermatitis, which is a reaction to a chemical or substance that comes into contact with the skin.
Eczema affects up to 7% of the population, and there is a family history of eczema in up to two-thirds of patients. Many patients with eczema have or will develop other allergic conditions such as asthma or allergic rhinitis. 80% have an elevation of an antibody called IgE, the antibody responsible for allergies, and all patients with eczema have a positive skin or other allergy test.
Food allergies are felt to play a significant role in atopic dermatitis. Virtually any food can be associated with a food allergy, but the three most common foods are milk, eggs, and peanuts, which account for 80% of all food allergies in children. In many cases, food allergies are associated with what has come to be called the “leaky gut syndrome.” In essence, the leaky gut is where larger and incompletely digested molecules of food are allowed to pass through the intestinal wall, where they are recognized as foreign, beginning an immune response. The immune response triggers not only the dermatitis, but can damage the intestinal wall, allowing more large molecules of food to pass, perpetuating the cycle.
Therapy of eczema can involve the use of steroids, either topical or sytsemic. Systemic steroids are associated with significant side effects and risks if used for chronically. Another topical therapy for eczema involving the feet is talc containing zinc.
While treating the rash directly can provide short term relief, the long term goal should be to address the underlying allergic cause. Food allergy testing can be done to identify foods that can trigger an allergic reaction. In this way, those foods can be targeted for elimination from the diet. If food allergy testing is not done, elimination of foods can be accomplished systematically through an elimination diet. In an elimination diet, foods are systematically removed then reintroduced back into the diet. By watching for improvement or worsening of symptoms, this allows a determination as to which foods are associated with an allergic reaction.
There are also tests that can be done to determine if patients have a “leaky gut.” If the leaky gut syndrome is present, an elimination diet alone may not be sufficient. This is because the problem involves not only an antigen-antibody reaction, but also improper digestion, which can be due to a variety of causes, and possibly damage to the bowel itself. This requires a separate program to restore proper digestive function and to promote healing of the bowel wall.
Essential fatty acids also play an important role in the treatment of eczema, particularly the Omega-3 fatty acids. Omega-3 fatty acids have anti-inflammatory properties, where as the Omega-6 fatty acids have inflammatory properties. As such, increasing the intake of Omega-3 fatty acids while decreasing the intake of Omega-6 fatty acids results in a reduction of inflammation, which is one of the inciting factors in eczema. As well, Omega-3 fatty acids are needed as building blocks in the production of cell walls. Since the skin has the highest turnover of cells in the body, Omega-3 fatty acids play an important role in healing the skin. The GI tract also has a very high turnover of cells, such that Omega-3 fatty acids would be needed for an improvement in GI function if a leaky gut were present. Omega-3 fatty acids can be obtained through dietary sources, such cold water fish, or through supplementation. Studies on supplementation show that fish oil supplements produce better results in eczema than flaxseed oil, borage oil, or evening primrose oil. For a more complete description of the Omega fatty acids and the foods that contain them, please see our section on Essential Fatty Acids.
Zinc is generally recommended along with Omega-3 fatty acids and fish oil as zinc is required for the metabolism of essential fatty acids.
An important component of the allergic process is the release of histamine. A number of herbal remedies have been shown to be effective in preventing the release of histamine. These include licorice (Glycyrrhiza glabra), Coleus forskolii, Ginkgo biloba, and the flavonoids, to include the flavonoids from grape seed, pine bark, and green tea.