Positive skin tests and Prausnitz-Küstner reactions in metabisulfite-sensitive subjects.

Sulfiting agents have been reported to cause anaphylaxis, asthma, urticaria/angioedema, seizure, nausea, abdominal pain and diarrhea, and death. There is no consensus regarding the pathogenesis of these reactions. The possible role of IgE-mediated mechanism has been debated. To clarify the pathogenesis of these reactions, we studied 53 patients with a variety of symptoms related to either restaurant meals or alcoholic beverages. Food allergy was excluded as a cause of their symptoms by means of skin testing and elimination diet. Symptoms included urticaria/angioedema (32), asthma (nine), headache (eight), rhinoconjunctivitis (two), and abdominal pain (one), and one patient with anaphylaxis. Twenty normal control subjects were studied as well. Prick and intradermal skin testing with potassium metabisulfite (K2S2O5, 1 mg/ml) were carried out on all subjects. Single-blind oral provocative challenge tests were conducted with placebo (lactose) and with 1, 5, 10, 25, and 50 mg of K2S2O5 in all nine subjects with asthma, nine patients with urticaria/angioedema (excluding one subject with severe coronary insufficiency and positive skin testing to 1 mg of K2S2O5), four subjects with headache, one subject with rhinoconjunctivitis, and one patient with anaphylaxis. Pulmonary function tests (FEV1 and FVC) were measured in all subjects with asthma. Five patients had positive skin tests. One subject with asthma had a positive prick test. Four positive intradermal tests occurred (two subjects with asthma, one subject with urticaria/angioedema, and one subject with anaphylaxis). Single-blind oral provocative challenge testing was positive in the subject with anaphylaxis, as was intradermal skin testing, and also in three subjects with asthma, two of whom had positive skin testing.(ABSTRACT TRUNCATED AT 250 WORDS)