Intolerance to sodium metabisulfite in children with steroid-dependent asthma.

Oral challenge tests were carried out with sodium metabisulfite solution doses of 5, 10, 25, 50 and 100 mg, dissolved in 20 ml of citric acid, and administered to 20 children aged 7-14 years with steroid-dependent bronchial asthma. A single-blind challenge protocol was performed initially and the positive responses were confirmed by double-blind challenge. Initially, 6 of 20 presented a positive reaction, confirmed in 4 of 20 by double-blind challenge. Only 1 child was clinically suspected of exhibiting intolerance to this agent. The prevalence of the challenge test using sodium metabisulfite in children with steroid-dependent bronchial asthma was 20%.