Allergic contact dermatitis of the lip margins from para-tertiary-butylphenol in a lip liner.

We describe the use of gas chromatography with mass spectrometry (GC-MS) in the investigation of a case of allergic contact dermatitis of the lip margins caused by a lip liner. Patch testing identified sensitization to para-tertiary-butylphenol-formaldehyde resin (PTBP-FR), a resin glue frequently used in leather work but rarely found in cosmetics. Investigation specified the para-tertiary-butylphenol (PTBP) component of the resin as the hapten responsible for the allergic contact dermatitis, as well as for associated depigmentation.