Contact sensitization to ingredients of dental materials and cosmetics in dental students: a pilot study.

OBJECTIVE: The aim of this study was to evaluate the rate of contact sensitization to selected cosmetic allergens, i.e. ingredients of dental materials, in students of dental medicine and dental patients. METHODS: A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied allergens during the course of practical education; and 10 randomly selected dental patients without occupational exposure to the investigated substances served as a control group. All of them were patch-tested with colophonium, myroxylon pereirae resin, paraben mix, fragrance mix I, isopropyl myristate, triclosan, polysorbate 80, compositae mix II, and hydroperoxides of limonene. RESULTS: The sensitization rates for colophonium and polysorbate 80 were the highest. For the group of dental students, we established significantly higher sensitization rate for colophonium compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 4.93; p = 0.026), paraben mix (χ2 = 3.6; p = 0.05), isopropyl myristate (χ2 = 6.56; p = 0.01), and triclosan (χ2 = 8.5; p < 0.001); and to polysorbate 80 compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 3.97; p = 0.046), isopropyl myristate (χ2 = 5.47; p = 0.02) and triclosan (χ2 = 7.34; p = 0.007). Significantly increased concomitant sensitization rate to compositae mix and to hydroperoxides of limonene was established (χ2 = 12.55; p < 0.001). Generally, the incidence of concomitant sensitization to the studied allergens in the whole studied population was high. CONCLUSIONS: Colophonium and polysorbate 80 could be outlined as sensitizers of paramount importance for both dental students and dental patients. We consider the major importance of exposure to colophonium during the course of practical education in dentistry for the onset of the sensitization. Sensitization to compositae mix was observed only among dental students. We consider the leading role of consumer exposure for the onset of the sensitization to triclosan and to hydroperoxides of limonene. Unexpected and unreported reactions of concomitant sensitization were observed.

Time trends of contact allergy to the European baseline series in Lithuania.

BACKGROUND: Monitoring trends of positive patch test reactions is useful for epidemiological surveillance and contact allergy prevention, and has not previously been reported in Lithuania. OBJECTIVES: To examine and compare changes in the prevalence of contact allergy to European baseline series allergens in adults with suspected contact dermatitis during a 9-year period. METHODS: In this retrospective study, patch test results of 297 consecutive patients, tested with the European baseline series in 2014-2015, were analysed and compared with the data published earlier in Lithuania. RESULTS: The most common allergens were nickel sulfate (30.6%), methylisothiazolinone (MI) (13.5%), methylchloroisothiazolinone (MCI)/MI (7.4%), potassium dichromate (6.1%), cobalt chloride (6.1%), Myroxylon pereirae resin (5.4%), p-phenylenediamine (5.4%), fragrance mix I (4.7%), formaldehyde (4.4%), and methyldibromo glutaronitrile (3.7%). Increases in the prevalence of sensitization to MCI/MI (2.3% in 2006-2008 and 7.4% in 2014-2015; p < 0.0001) and nickel sulfate (16.4% in 2006-2008 and 30.6% in 2014-2015; p < 0.0001) and decreases in the prevalence of sensitization to paraben mix (3.2% in 2006-2008 and 0.3% in 2014-2015; p = 0.006) were observed. Prevalences for the other allergens remained stable or showed a decreasing trend (Myroxylon pereirae resin; p = 0.06). CONCLUSION: This study provides current information on the prevalence of contact allergy in Lithuania. Changing trends in sensitivity to some allergens probably reflect changes in exposure.

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

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.