Decreasing trends in methyldibromo glutaronitrile contact allergy – following regulatory intervention

Abstract

BACKGROUND: The preservative methyldibromo glutaronitrile (MDBGN) has been banned, first from stay-on, and later from rinse-off cosmetics, in the EU countries because of increasing rates of contact allergy. OBJECTIVES: To evaluate the frequency of contact allergy to MDBGN among patients patch tested by the Danish Contact Dermatitis Group just before and following regulatory decisions. PATIENTS/METHODS: The data set comprised 19 279 consecutive eczema patients patch tested from 2003-2007 with MDBGN 0.3% in petrolatum (pet.) or, in a minority of patients, with Euxyl K 400 1.5% in pet. RESULTS: A significantly decreasing trend in the frequency of positive patch tests to MDBGN was found from 4.6% in 2003 to 2.6% in 2007 (P < 0.001). The decreasing trend was seen for both men and women. A significantly decreasing proportion of cases with a current relevance of contact allergy to MDBGN was also seen from 51.3% in 2003 to 29% in 2007 (P < 0.001). CONCLUSIONS: Regulatory interventions have already had a major effect on allergic disease due to MDBGN in Denmark. The same trends are likely to be seen in other EU countries.