Contact allergies to the preservatives formaldehyde and methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI) have been reported to appear together at a statistically significant level. Recently, revisions concerning the patch test preparations of MCI/MI, MI and formaldehyde have been recommended for the European baseline series.
To investigate (i) the number of concomitant contact allergies to the preservatives, (ii) the number of concomitant contact allergies to the preservatives and the fragrance mixes (FM I and FM II) and (iii) gender differences.
Patients tested with the Swedish baseline series during the period 2012-2014 at the Department of Occupational and Environmental Dermatology in Malmö, Sweden were investigated.
2165 patients were patch tested with the baseline series (34% males and 66% females). Contact allergies to formaldehyde and MCI/MI and/or MI were significantly associated (p?