INCREASING INCIDENCE OF CONTACT ALLERGY TO THE NEW PRESERVATIVE 1,2-DIBROMO-2,4-DICYANOBUTANE (METHYLDIBROMOGLUTARONITRILE)

In 1991, only a low frequency (0.5%) of sensitization by the newly int roduced preservative 1,2-dibromo-2 4-dicyanobutane (synonym: methyldib romoglutaronitrile; trade names: Euxyl K400, Merquat 2200, Tektamer 38 ) was encountered in the Netherlands, It has subsequently been increas ingly used in our country as a preservative in moistened toilet tissue s, and also in cosmetics such as body milk, lotions and creams. This p rompted us to re-evaluate the frequency of sensitization. From January 1993 until July 1994, all consecutive patients attending for routine patch testing were also tested with 1,2-dibromo-2,4-dicyanobutane (0.1 % petrolatum): one of 281 (0.3%), nine of 281 (3.2%) and six of 247 (2 .4%) were found to be positive in the first and second halves of 1993 and the first half of 1994, respectively. In at least 12 of 16 patient s this allergy was responsible for their presenting complaint (periana l and facial dermatitis). As 12 of 16 patients had intensively used mo istened toilet tissues containing this preservative, this habit is pre sumably the cause of sensitization, Our data indicate that the frequen cy of sensitization is approaching that of allergy to methyl(chloro)is othiazolinone (Kathon CG; 1993: 2.3% in our hospital), a well-known al lergen, which seems to have been partially replaced in cosmetics and t oiletries by this new preservative.