Allergic contact dermatitis from sodium metabisulfite in a topical preparation

A 31-year-old woman with psoriasis developed acute allergic contact dermatitis during a topical drug trial. After healing of the contact dermatitis, epicutaneous test results showed a positive reaction to the drug as well as the placebo cream. Patch testing with ingredients showed a positive reaction (2+) to sodium metabisulfite and dilutions thereof.