Preservatives sensitivity in Israel: a 10-year overview (1995-2004)

This study presents a 10-year survey of 2285 patients tested to common preservatives in northern Israel. The demographic and clinical data were analysed using a revised MOAHLFA index. Patch testing was based on the International Contact Dermatitis Research Group (ICDRG) guidelines. 411 (18%) patients were found to have positive reactions to 1 or more preservatives. The most frequent allergens tested positively were thimerosal, methylchloroisothiazolinone/methylisothiazolinone (MCI/MI), and formaldehyde. The reactions to MCI/MI remained stable around 1.7% throughout the years 1995-1998, with a significant increase to 3.7%-4% (P = 0.029) during 1999-2004. The reactions to formaldehyde remained low around 0.3% until 1999; however, a considerable increase throughout the years 2000-2004 was noted, with rates of 1.5%-1.9% (P = 0.028). The sensitivity rates for parabens, quaternium-15, imidazolidinylurea, and diazolidinylurea were low and unchanged, mostly under 0.5%. As for methyldibromoglutaronitrile (MDBGN), sensitivity rates around 2% were detected for the years 1996 and throughout 2000-2004. Overall, this extensive survey showed a concerning increase in the sensitivity rates for MCI/MI, formaldehyde, and MDBGN.