We describe an 18-year-old dental technician who presented with dry hyperkeratotic lesions on his left palm that were limited to an area that was in contact with a container in which he had prepared the molds for a dental prosthesis. On patch testing, he had a positive reaction to black rubber mix and its components N-cyclohexyl-N'-phenyl-4-phenylenediamine, N,N'-diphenyl-4-phenylenediamine, and N-isopropyl-N'-phenyl-4-phenylenediamine, as well as to a piece of the rubber container. Thin-layer chromatography (TLC) of a piece of the rubber container confirmed the presence of the para-phenylenediamine mix. Results of patch-testing with TLC were positive after 48 and 96 hours. The lesions resolved when the patient stopped using the container. The patient was diagnosed with occupational allergic contact dermatitis. We also review the dermatoses caused by antioxidant amines.