Chapter 62 - Polyphenols and Polyphenol-Derived Compounds and Contact Dermatitis

Abstract

Polyphenols and polyphenol-derived compounds from plants are common causes to skin reactions resulting in allergic contact dermatitis, photodermatitis and/or irritant dermatitis. Allergic contact dermatitis is the most common skin reaction caused by plant products. Characteristic for many contact allergens is their ability to react with skin proteins in a Michael addition reaction generating an antigen leading to an immunological response; for example, eczema. Most contact allergens of polyphenol origin are reactive quinones or polyphenols that are oxidized to quinones in the skin. Unlike allergenic substances, chemical irritants or phototoxic compounds will affect all subjects on the first exposure. Irritants typically results in a cutaneous inflammatory response whereas phototoxic compounds leads to a bullous, erythematous eruption of the skin on light-exposed areas. Some polyphenols have anti-inflammatory activity and/or can inhibit the activation and proliferation of T cells, thus being able to alleviate symptoms of skin inflammation and contact hypersensitivity.