Contact sensitivity to parachlorometaxylenol (PCMX)

A retrospective analysis of patch test results in 951 patients found 17 (1·8%) who had positive reactions to parachlorometaxylenol (PCMX). None of these reactions had been predicted prior to patch testing. In seven cases, there was direct relevance to the patients' rash and in six patients there was evidence of past relevance. Most of our patients were sensitized by popular proprietary preparations containing PCMX. Although not a common sensitizer, we believe that PCMX should be included in the standard battery in areas where there is widespread use of PCMX‐containing preparations.