[A new allergen dibromodicyanobutane. Report of a study in 310 patients January-December 1994]

Methylisothiazolinone chloride (Kathon CG) and its derivatives, used as preservatives in cosmetics, have been shown to be allergenic when used in humans although preliminary studies in Guinea pigs failed to reveal any sensitization. Dibromodicyanobutane, associated with phenoxyethanol in Euxyl K400, has been proposed to replace the isothiazolinone derivatives in cosmetics. Preliminary study has shown that these thiazolinone derivatives are not allergenic in Euxyl K400. The similarity of these situations led us to hypothesize that dibromodicyanobutane could become allergenic.

We tested 0.1 p. 100 dibromodicyanobutane in vaseline in the additional battery of the ICDRG battery in patients with contact eczema. Among the 310 patients tested, 1.94 p. 100 had a positive test for this allergen (during this same period, 1.29 p. 100 of the patients were positive for isothiazolinones). Three patients were hospitalized because of generalized eczema and 1 patient had changed occupation with no effect because the crems containing the allergen had not been avoided.

Dibromodicyanobutane is a new allergen. Numerous cases of allergy have developed as use of the product becomes more widespread. The consequences of this sensitization may have an economic impact. Animal experimentation has been unable to predict this allergenic effect. Cosmetic products must be precisely labeled with a single international term for each specific molecule and the name of the preservative added to the active substance.