Sulphite allergy

Sulphites are chemicals that have anti-microbial and antioxidant properties. They are widely used as preservatives in foods, beverages and medicines. They protect these substances from contamination by microbes, and prevent browning and spoilage.

They have literally been used for hundreds of years and this extensive experience has understandably strengthened confidence in their safety. However, over the past decade there have been a number of reports of adverse reactions to sulphites. There are no reliable statistics on the incidence of sulphite sensitivity but it is generally agreed that it predominantly occurs in asthma sufferers. Some authorities have suggested that 5-10% of all chronic asthmatics are sulphite hypersensitive. It is uncommon in pre-school children, and steroid-dependent asthmatics are thought to be more at risk.

The sensitivity reactions vary widely depending on the individual. Fortunately most recorded reactions are mild such as a transient rash, cough and catarrh, or stomach upset. The most common reaction is difficulty breathing from constriction of the airways – a symptom obviously very familiar to an asthmatic. Rarely, the reaction may be more serious and severe anaphylactic reactions have been reported.

Practically, what all this means is that sulphites need to be added to the long list of substances that can be harmful to a few sensitive individuals who probably already suffer from asthma. The names to look out for on the label are sulphur dioxide and sodium or potassium bisulphite, sulphite or metabisulphite.

Information written by the talkhealth medical panel

Last Reviewed: 28 March 2011
Next Review Date: 30 September 2012