Patch Testing With Preservative Sensitizers. A Year Retrospective Study From Selayang Hospital

ABSTRACT

Abstract Introduction: Other than nickel, fragrance and rubber, preservatives are well known sensitizers. Objectives: To study the pattern of preservative allergy among patients patch tested at Patch Test Unit Selayang Hospital. Materials & Methods: We conducted a retrospective analysis of the data of all the patients patch tested with preservative sensitizers present in the European Baseline Series and other commercial series in Selayang Hospital from January 2011 to December 2011. Results: 243 patients were patch tested. 28.4% of the patients had a positive reaction to one or more of the preservative sensitizers. Paraben mix was the most frequently positive allergen (11.8%). 17.8% of the Indians had paraben allergy, as compared to 11.3% of Malays and 11.2% of Chinese. Females were more significantly associated with a positive reaction to one or more of the preservative sensitizers (p=0.010). A younger age group (<35) was more significantly associated with formaldehyde allergy. “Face and upper limbs combined” presentation was significantly associated with a positive reaction to formaldehyde and methylchloroisothiazolinone/ methylisothiazolinone (p=0.042 and p<0.001 respectively). Conclusion: Our data differ from most other countries in that paraben mix was the most frequently positive preservative sensitizer and that younger age group was significantly associated with sensitization to formaldehyde.