Dicaprylyl maleate (DCM) may rarely cause allergic contact dermatitis. An international study identified patients from multiple centres with allergy to fresh and aged DCM in cosmetics by patch testing. Twenty-two patients with 26 reactions to products containing DCM were studied. Twenty-two patients had clinical and positive patch test reactions at 4 days to a total of 26 DCM-containing products. Five patients had no reactions to fresh DCM but did so to a deliberately aged DCM sample (Lotery, H. et al. Contact Dermatitis 2007, 57(3): 169-172).