[Red pigment dyes and acne. Clinical observations and experimental investigations (author's transl)]

Acne-like changes were observed on a child's cheeks after colouring them with a red felt-tip pen. Numerous comedos appeared around a red tattoo coloured with felt-tip pen ink on a 16 year old girl. In animal experiments using rabbits' ears, two organic pigment inks found in these types of felt-tip pens could be proved to be the cause of a comedo-producing reaction. We are concerned here with quinacridone dye, pigment violet 19 (C.I.46.500), and the chlorine containing azo dye, pigment red 7 (C.I. 12.420).