Natural Ingredients in Atopic Dermatitis and Other Inflammatory Skin Disease

increased textural skin improvement. One further practical application has been the use of feverfew in the prevention and treatment of shaving irritation.¹⁶ Most interesting, however, are the preclinical studies using normal human epidermal keratinocytes, which showed that when feverfew extract was added immediately before UV exposure to the cells, inhibition of the release of reactive oxygen species (ROS) in a dose-dependent fashion was observed.^17,18

A similar potent antioxidant effect was noted in an experiment measured from skin cells acquired by tape stripping. Various moisturizing products each containing different ingredients that claim antioxidantive properties were applied to the volar forearm of panelists, one of them containing feverfew extract. After 4 hours, skin cells were tape stripped and assessed for ROS ex vivo. Only the product containing feverfew significantly inhibited ROS production. Applying these results to skin in the context of UV exposure suggests potential clinical use as a sun-protective agent.

Chamomile has a long-standing history in folk medicine both internally and externally, mainly for gastrointestinal symptoms but also as a skin soothing agent and aromatherapy ingredient. The flower’s active ingredients are flavonoids, volatile oils, courmarines, mucilages, and saccharides, which show inhibition of cyclooxygenase, lipooxygenase, and histamine. Chamomile is well tolerated when used topically, and is frequently used for minor irritations of the skin, comparable in its efficacy to 0.25% hydrocortisone cream for AD. In a study in Helsinki, 48 women who had undergone surgery for breast cancer applied chamomile cream above the wound area and almond oil below the wound area half an hour prior to radiotherapy and again at bedtime. Chamomile appeared to delay the onset of radiation dermatitis and reduced the severity grade compared with almond oil, even though neither was able to prevent radiation dermatitis altogether or prevent symptoms of itchiness and pain.^19-21

Aloe vera has long been known for its anti-pruritic, analgesic, bactericidal, antifungal, and health-promoting effects. Active components include salicylic acid, magnesium lactate, and polysaccharides gel, which decrease thromboxane A2 and B2 and prostaglandin 2a, and function as lipid radical scavengers. Studies have in particular underscored its skin-healing properties in psoriasis.²²

Licorice exerts its anti-inflammatory and skin lightening properties via glabridin, licochalcone A, and liquiritin, and has been shown to be suitable even for sensitive skin. Glabridin is the main active ingredient derived from Glycyrrhiza glabra and is a constituent in many different botanicals. It is known to have anti-irritant effects through inhibiting superoxide anion production and as a cyclooxygenase inhibitor. The licorice extract licochalcone A is derived from a different kind of licorice plant grown in northwest China, Glycyrrhiza inflate. It appears to exert it’s own anti-irritant effect via the same biochemical pathways. Liquiritin is a flavonoid in licorice that along with other components imparts the natural yellow color.^23,24 Studies of a skin care regimen containing a licochalcone A based cleanser, SPF 15 lotion, spot concealer, and night cream applied over 8 weeks showed good redness-neutralizing properties that were confirmed using cross-polarized photographs.²⁵ Liquiritin applied in the clinical setting for idiopathic epidermal dyspigmentation has been shown to exert a skin brightening effect in a vehicle controlled 4-week study.

Dexpanthenol is another natural that has long been treasured for its skin healing and soothing properties, and historically used on superficial wounds, burns, and dermatitis. Pantothenic acid, a member of the vitamin B5 complex, is essential to normal epithelial function and a component of co-enzyme A. Studies have shown significant reduction in itching and burning in AD patients using a colloidal oatmeal bath with ceramides and dexpanthenol.²⁷

The traditional use of natural ingredients, which was largely based on empiric evidence and folk medicine recipes, has been completely updated and scientifically validated by recent bench side and clinical research. An increasing body of scientific data now supports their use in various clinical settings, and new indications are continuously emerging. Most of the “new naturals” are specifically considered safe for sensitive skin; however, caution should be used when applying oil-based products such as tea tree oil, camphor oil, and lavender oil. These naturals have been shown to be useful as adjunct treatment in a variety of inflammatory skin conditions, including AD, contact dermatitis, drug-induced cutaneous rashes, and burn injuries. They have in particular emerged as alternative options in the treatment of pediatric patients, where the concern about potential side effects of topical steroids and/or calcineurin inhibitors remains a major consideration. These “new naturals” are expanding our treatment choices for the management of inflammatory skin disorders on an ongoing basis, with new emerging usage and research data supporting their strong reputation as safe and effective options.

Magdalene A. Dohil MD has served as a speaker and on an advisory committee for Johnson & Johnson Consumer Companies, Inc.