Evening Primrose for Atopic Dermatitis
Atopic dermatitis (AD) is a chronic condition and the most common type of eczema that affects more than 16 million adults and nearly 10 million children in the U.S. It often appears early in life with flareups that occur intermittently throughout life, sometimes in conjunction with other types of eczema. Although the exact cause is not well understood, AD appears to be driven by an overactive immune system and the deterioration of the skin barrier from chronic inflammation. The result is rash-like patches of skin that feel dry and relentlessly itchy, a condition that often worsens with cold weather. In some people, AD is exacerbated by a gene mutation that depletes filaggrin, a protein necessary to maintain the integrity of the skin barrier. This makes the skin prone to infections from the penetration of harmful surface bacteria and viruses. Persistent scratching may lead to hardening of the skin in a process called lichenification.
Conventional treatment typically consists of topical corticosteroids, which suppress the entire immune system. While these are effective in reducing immune response, they present the risk of unwanted side effects with long-term use. The skin is the body's largest organ and the gateway to the blood stream, and using these topicals can lead to Cushing's syndrome in children, high blood sugar levels, osteoporosis and a discoloration of the skin from erythematoedematous.
Biologics are also commonly used to treat AD. Unlike corticosteroids, biologics consist of immune modulators and monoclonal antibodies produced from human plasma that target specific proteins responsible for causing inflammation. Some of these agents are TNF (tumor necrosis factor) inhibitors, which increases the risk of infections (including tuberculosis) and the development of congestive heart failure, drug-induced lupus and cancer.
A natural approach to managing AD includes adhering to a diet rich in whole foods and as free of preservatives, artificial flavors and colors as possible, as well as adequate sleep and stress management. Quality skin care products -- again, as organic as possible -- are also helpful to keep the skin barrier in good shape while providing instant relief. Certain botanicals may also help. However, while we have centuries of herbal wisdom to draw from, there a few clinical studies to reference and no systematic review of the available literature -- that is, until now.
Researchers at the University of Bern Institute of Complementary and Integrative Medicine in Switzerland, screened 429 articles pulled from PubMed, EMBASE, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Based on Jadad score (aka Oxford quality scoring system), the team eliminated studies that didn't meet their criteria and ended up with 17 studies for a total of 2,358 participants. Of these, seven were focused on treatments for atopic dermatitis and skin lesions or wounds, and three were dedicated to diaper dermatitis. The therapeutic agents investigated included evening primrose, blackcurrant, polypodium leucotomos, calendula, aloe vera, chamomile, comfrey, hamamelis, olive, hypericum, neem, white oak, and myrrh. The scientists found that evening primrose oil showed the most promise in treating atopic dermatitis in children.
Evening primrose (Oenothera biennis), also known as evening star, hog weed, King's cure-all, sundrop and fever plant, is a flowering, spreading herb in the Onagraceae or willowherb family commonly referred to as primroses. It is a popular ornamental plant and valued for it's clusters of sunny yellow flowers that honeybees love to visit, although the plant is edible. In fact, the Anishinaabe peoples of Canada and the U.S. traditionally make tea from the leaves, cook the roots as a vegetable, and prepare the boiled and mashed roots as a poultice for various skin conditions. The seeds, an important food for several species of birds, can remain dormant in the soil and viable for more than 70 years.
The seeds are also the source of evening primrose oil. While the leaves and roots of the plant provide a variety of flavonoids, phenolic acids and fatty acids, the seeds yield an oil that is up to 74% linoleic acid (LA) and up to 10% γ-linolenic acid (GLA), which are metabolized into agents that inhibit the production of inflammatory mediators that trigger immune response, such as leukotriene A, cytokine and interleukin 6 (IL-6).
Evening primrose oil is readily available in economic capsule form. It may be applied topically by blending the contents of one or two capsules with a small amount of lotion or a carrier oil, such as sweet almond oil. Note, however, there is little evidence that oral supplementation is effective against AD or any other skin condition.
While evening primrose oil is safe for most people, check with your health care provider before using it if you take certain medications, most notably drugs effected by cytochrome P-450 enzymes, HIV medications and phenothiazines.
By Karyn Maier
References
Kloter E, Albanese F, Schweighoffer R, Wolf U. Phytotherapy in paediatric skin disorders - A systematic literature review. Complement Ther Med. 2023 Jun;74:102942.
Timoszuk M, Bielawska K, Skrzydlewska E. Evening Primrose (Oenothera biennis) Biological Activity Dependent on Chemical Composition. Antioxidants (Basel). 2018 Aug 14;7(8)
