Sulfites can be a cause of asthma and allergy symptoms that can range from mild wheezing to potentially life-threatening anaphylactic reactions. You can find sulfites in certain foods and beverages, as well as a variety of medications. If you have a sulfite allergy, it’s important to check food labels for sulfites so you can avoid a reaction.
Sulfites are chemicals used as preservatives to slow browning and discoloration in foods and beverages during preparation, storage and distribution. Sulfites have been used in wine making for centuries.
You can find sulfites in certain foods and beverages, as well as a variety of medications. The use of sulfites as preservatives in foods and beverages increased dramatically in the 1970s and 1980s. Due to cases of severe reactions to sulfites, a ban by the Food and Drug Administration (FDA) went into effect in August, 1986. This ban prohibited use of sulfites in fresh fruits and vegetables.
Although reactions to sulfites were recognized initially with salad bars in restaurants, this has not been a source for sulfite exposure for more than three decades. Sulfites continue to be used in potatoes, shrimp, and beer/wine, and are also used in the pharmaceutical industry. Sulfites are added to many medications, including some of the medications given to treat asthma and allergic reactions.
Sulfites have been implicated as a cause of asthma symptoms that may range from mild wheezing to potentially life-threatening asthmatic reaction. It is also a very rare cause of anaphylaxis (generalized allergic reaction) in people who have become allergic to sulfites.
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People with sulfite-sensitive asthma experience asthma symptoms when they eat foods or drink beverages that contain sulfites. Estimates regarding the prevalence of sulfite sensitive asthma vary. Most reactions happen due to inhalation (breathing in) of sulfur dioxide that comes from sulfite-containing foods you eat or drink.
Your doctor may suspect sensitivity to sulfites based on your medical history and aspects of your asthma. The diagnosis of sulfite sensitivity can be confirmed by a "challenge" in which sulfite is administered in solutions or capsules of increasing concentration.
The challenge is done in a step-by-step fashion. Small doses of sulfite are used, so the asthma reaction that happens is usually mild. In most cases, the initial solution dose is too small for the sulfite-sensitive person to react, so increasing doses are administered, waiting 20 to 30 minutes between steps. Once a reaction takes place, it’s measured — by lung function studies (or "spirometry") — and can be quickly reversed with an inhaled bronchodilator medication. The entire challenge procedure takes less than 2 to 2-1/2 hours.
If you have a sulfite sensitivity, you’ll want to avoid the things that trigger your condition. This is very similar to learning to avoid other allergens or irritants if you have asthma.
If you have a sulfite sensitivity, there are ways to avoid accidently consuming items that could trigger your condition. Check for these sulfite-containing ingredients on the label of your food, beverage or medication:
If you’re not asthmatic, sulfite sensitivity would be very unusual. If you do have asthma, your chances of being sensitive to sulfites is in the range of between 1 in 40, and 1 in 100. If you suspect you may be sensitive to sulfites, you should be evaluated by a board-certified Allergy/Immunology physician before starting on a program of lifelong avoidance of foods and beverages that contain sulfite.
A note from Cleveland Clinic
If you have a sulfite sensitivity, you’ll need to avoid substances containing sulfites throughout your life. Talk to your healthcare provider for directions on what to avoid and what to do if you ever have a reaction.
Last reviewed by a Cleveland Clinic medical professional on 10/16/2020.
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