Contact dermatitis from antioxidants.

Abstract

In a search for contact sensitivity to antioxidants, consecutive patients referred with eczematous dermatitis were patch tested. Six cases of allergic contact sensitivity to nordihydroguaiaretic acid (NDGA) were observed. Three were sensitized by 1 brand of cream containing 0.1% NDGA; in 3 patients the source of sensitization could not be traced. In 4 patients, positive patch tests to butylated hydroxyanisole and/or to butylated hydroxytoluene was found. In 2 cases, the positive patch tests were relevant, since both patients remained asymptomatic when antioxidants were avoided in food. They both had acute flares of vesicular eczema on the fingers after oral administration of small amounts. Gallate esters and vitamin E (d,l-.alpha.-tocopherol) each gave 1 unexplained positive patch test. A further search for hidden sensitizers in topical medicaments and cosmetics is apparently warranted. A declaration of all ingredients in industrial products should be placed on the label.