Skin sensitization to cinnamic alcohol: the role of skin metabolism.

Cinnamic alcohol and cinnamic aldehyde are a cause of allergic contact dermatitis in man and give rise to similar rates of positive reactions in routine patch testing. However, data from animal models indicates that the aldehyde is the stronger sensitizer of the two. Circumstantial evidence has pointed to the conversion of alcohol to aldehyde in skin as the cause of cinnamic alcohol sensitization. This report discusses the subject in the light of studies of skin metabolism of cinnamic alcohol. Evidence of limited cross reactivity between cinnamic alcohol and cinnamic aldehyde is supported by data showing conversion of cinnamic alcohol to cinnamic aldehyde by an epidermal enzyme.