What Ingredients Should You Avoid If You Have a Sulfa Allergy?

Those with a sensitivity toward sulfites or a sulfite allergy should avoid products containing the following ingredients: sulfur dioxide, potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium metabisulfite or sodium sulfite, according to WebMD. These are often found in processed or cooked foods as well as in wine and beer.

Sulfites are commonly used as an additive in the preservation process of many preserved or dried food products. Sulfites also occur naturally during the fermenting process of beer and wine. A sulfite allergy can occur at any point in a person's lifetime and can range from mild to severe.

The use of the preservative increased in the 1970s and 1980s which correlated with an increase to sulfite-adverse reactions, says the Cleveland Clinic. In 1986, the Food and Drug Administration banned the use of sulfites on fresh fruit and vegetables although some sulfites are still used on potatoes.

Some medications made with sulfites, or sulfonamides, can cause an allergic reaction, says The Mayo Clinic. These medications include Sulfamethoxazole-trimethoprim, Erythromycin-sulfisoxazole, Sulfasalazine and Dapsone as well as others.

Sulfites have been linked to the presentation of asthmatic symptoms in an allergic individual, according to the Cleveland Clinic. Those experiencing asthmatic-like symptoms such as wheezing often do so as a result of aspirating the chemical while in the process of eating a sulfite-tainted food.