Botanical dermatitis

Abstract

Cosmetic products increasingly contain numerous preparations derived from the roots, stems, flowers, etc. of plants. These botanical ingredients are frequently used for “cosmaceutical” purposes. Although widely perceived by the public as “safer” than synthetic ingredients, Corazza, et al. (J. Eur. Acad. Dermatol. Venereol. 2009; 23: 1298) concluded that botanical preparations were a potential source of adverse skin events, and that lack of adequate patch testing in cases of suspected contact allergic dermatitis, incomplete or misleading product labelling, and the risk of chemical adulteration may represent further concerns for botanicals. Simpson, et al. (Dermatitis 2004; 15: 67) proposed the following screening allergens for suspected botanical dermatitis: tea tree oil, lichen acid mix, geranium oil, spearmint oil, dandelion, neroli oil, and lavender, sandalwood oil, cananga oil, rose oil, ylang-ylang oil, and compositae mix. However, my experience, and that of others, has been that these allergens miss a significant number of cutaneous botanical reactions. When the suspicion of plant-derived dermatitis exists, one can patch test “leave on” cosmetic products as is; but, for “rinse offs”, testing is typically performed at aqueous dilutions of 1:2, 1:10 and 1:20; and, for “rinse offs” allergic responses need to be carefully differentiated from irritant. One can also patch test with as wide an array of commercially available fragrance and plant allergens as possible; however, if patch tests are negative, botanical contact dermatitis cannot de facto be ruled out. When in doubt, use testing (ROAT) with “leave-ons” as is and “wash-offs” in an aqueous dilution (1:10) can be performed. As a last resort, the elimination of fragrances and plant-derived ingredients from personal care products and supplements may be considered.