Allergy to preservatives

: This study concerns 465 patients with dermatitis. The clinical history suggested allergy to cosmetics, drugs, industrial products or clothes. These patients were tested with 29 preservatives chosen among the most frequently employed or most sensitising products. Seven french clinics of Dermatology were involved in this study during one year. The patients' age varied between 2 years old and 80 years old. Positive reactions were seen mostly with formaldehyde (4.7 p. 100), Bronopol (4.7 p. 100), ammoniated mercury chloride (3.8 p. 100), benzoic acid (2.1 p. 100), sodium benzoate (1.9 p. 100), parabens (1.9 p. 100), dichlorophen (1.7 p. 100), chloracetamid (1.5 p. 100), benzyl benzoate (1.5 p. 100), Germall 115 (1.2 p. 100), butylhydroxyanisol (1 p. 100) and Dowicil (0.8 p. 100). The incidence of sensitivity to formaldehyde, Bronopol, ammoniated mercury chloride is too high; their use should decrease. Patients sensitive to benzoic acid, benzyl benzoate are not rare. Chloracetamid whose frequency of uses seems to be rather low is a very sensitising product. Parabens which are widely used were seldom found positive; nearly all cases are caused by topical medications.