[Occupational asthma to metabisulfites . Three cases].

Sulfites are compounds which are mainly used in the agricultural, food and pharmaceutical industry as preservatives. The possibility of manifestations of acute hypersensitivity appearing after the ingestion or inhalation of sulfites has already been described several times, over the past twenty years. Amongst these manifestations and indeed the one that is most often present is bronchospasm, which can sometimes be severe.