METHYLDIBROMOGLUTARONITRILE IS AN IMPORTANT CONTACT ALLERGEN IN THE NETHERLANDS

From 15 May to 15 December 1994,2943 patients suspected of having cont act dermatitis (1955 women, 988 men) were patch tested with methyldibr omoglutaronitrile 0.3%, 0.1% and 0.05% pet. 119 patients (4.0%; women 4.1%, men 3.8%) proved to be allergic. 71% of the reactions were consi dered to be relevant. In 2/3 of the patients, causative products were cosmetics, in 1/3 moistened toilet tissues. Testing with methyldibromo glutaronitrile at lower concentrations (0.05% and 0.1%) and with comme rcial allergens (Euxyl(R) K 400 and methyldibromoglutaronitrile, both containing methpldibromoglutaronitrile 0.1%), resulted in a number of false-negative reactions. All preservatives in the European standard s eries had lower scores than the 4% positive reactions to methyldibromo glutaronitrile (formaldehyde 2.0%, MCI/MI (Kathon(R) CG) 3.2%, paraben s 1.0%, quaternium-15 1.3%). It is concluded that methyldibromoglutaro nitrile (present in the commercial preservative Euxyl(R) K 400) is an important contact allergen in the Netherlands in cosmetics and moisten ed toilet tissues. It should be added to cosmetics series and to proct ological series. The optimal test concentration is unknow, but may be 0.3% pet. The concentration of 0.1% methyldibromoglutaronitrile in the currently available commercial allergens appears to be too low, resul ting in a number of false-negative reactions. (C) Munksgaard, 1996.