Metabisulfite sensitivity: case report and literature review.

Sulfiting agents have recently been identified as food and drug additives responsible for adverse reactions. These reactions are not rare and may result in life-threatening asthma and anaphylaxis. We report a 34-year-old female with intractable asthma and urticaria. Sensitivity to sulfites was suspected based on exacerbation after restaurant meals and metaproterenol 5% inhalant solution. Bronchial provocation challenge resulted in a 28% decrease in FEV1 and a 34% decrease in FEF25-75 at the 0.01 mg/ml dose. Thirty-two cases of sulfite sensitivity reported in the literature are reviewed. Foods and drugs containing sulfites are listed. The pathogenic mechanism is unknown. The FDA allows the addition of sulfites to foods and drugs without disclosure. Only recently has this potential hazard been recognized. The FDA is considering a labeling requirement on drugs that do contain sulfites.