An unusual case of sensitization to methylchloro- and methyl-isothiazolinone (MCI/MI).

This article presents the case history of a 47-year-old psychologist with a one year history of widespread dermatitis, favoring the axillae and breasts, though the face was also affected. High performance liquid chromatography analysis was performed on the paint, a shampoo and 6 cleaning products used in her office. The paint, the shampoo and one of the 6 cleaning products, the furniture wax, contained methylchloro-isothiazolinone/methyl-isothiazolinone MCI/MI. The former two showed signs of degradation of MCI, as the ratio between MI and MCI was less than 3. It was estimated that the total a.i. level for the paint was 32.56 ppm and for the shampoo 2.24 ppm.