Sulfite Sensitivity

What is a sulfite allergy or sulfite sensitivity?

Sulfite allergies and sensitivities are conditions that most often affect people with asthma. They can cause asthma attacks (wheezing, coughing or shortness of breath) or allergy symptoms (sneezing, runny nose or hives) when you ingest or come in contact with foods, drinks or medications with sulfites in them.

Sulfite sensitivity is more common than a true (IgE-mediated) sulfite allergy and often triggers your asthma.

What are sulfites?

Sulfites are chemicals used as preservatives. This means they prevent food, beverages and medications from spoiling (“going bad”). They’re often used to slow browning and discoloration (caused by bacterial growth) in foods and drinks. For instance, winemakers have used sulfites for centuries to preserve the color and flavor of wines. Sulfites also occur naturally in some foods and beverages.

Sulfites are not the same as:

• Sulfur (an element found in nature).
• Sulfa drugs (a class of antibiotic medications). But some people experience sulfa allergies.
• Sulfates (sulfuric acid salts that are often found in personal hygiene products, like toothpaste, shampoo or soap).

How common is sulfite allergy or sensitivity?

About 4% to 5% of people with asthma have some form of sulfite sensitivity.

What are the symptoms of a sulfite allergy?

Symptoms of sulfite allergy or sensitivity include:

• Wheezing.
• Shortness of breath (dyspnea).
• Chest tightness.
• Coughing.
• Sneezing
• Stuffy or runny nose.
• Hives.

Rarely, people with a sulfite allergy can have anaphylaxis, a severe allergic reaction. This can cause:

• Difficulty breathing or swallowing.
• Flushing (your skin swelling, getting hot or turning red).
• Fast heartbeat (tachycardia).
• Severe wheezing.
• Dizziness.
• Vomiting.
• Diarrhea.

Why do sulfites make me sick?

Experts aren’t sure what causes sulfites to trigger allergies or asthma attacks. Some factors that could contribute include:

• Reactions to inhaling sulfur dioxide. Sulfites release sulfur dioxide gas. You might inhale it when you swallow things with sulfites in them. This could cause your airways to swell up and narrow, worsening asthma symptoms.
• IgE-mediated reactions. IgEs are antibodies, or proteins that recognize harmful substances. Sometimes, antibodies recognize things that aren’t harmful and mistakenly tell your immune system to destroy them. This causes allergies.
• Low levels of sulfite oxidase. Sulfite oxidase is an enzyme that breaks down sulfur dioxide. Some people with asthma have low levels of the enzyme, which can mean they don’t clear sulfites out of their bodies as easily as they should. This might cause allergic or asthma reactions.

Who’s at risk for sulfite sensitivity?

People with asthma are more likely to have reactions to sulfites than people without asthma. Having other food allergies may also put you at an increased risk.

Can you be sulfite sensitive without asthma?

Some people who are sensitive to sulfites don’t have asthma. But people without asthma very rarely have serious reactions to sulfites.

How do you test for sulfite sensitivity?

Healthcare providers diagnose a sulfite allergy or sensitivity based on:

• Your symptoms.
• Your medical history.
• Whether or not you have asthma or other allergies.
• A food challenge test.

There isn’t a reliable blood or skin test for sulfite allergy.

Sulfite food challenge

During a challenge test, an allergist will give you small, increasing amounts of sulfite (usually in a liquid or capsule) and see if you have a reaction. If you do, your provider will measure your lung function with a spirometer. They’ll have medication to treat you so you don’t progress to a severe reaction.

How do you treat sulfite sensitivity?

If you have a sulfite allergy or sensitivity, it’s important to try to avoid foods, drinks and medications that contain sulfites. A healthcare provider might also treat you with:

• Cromolyn. This is an anti-inflammatory medication that stabilizes mast cells (cells that cause allergies).
• Corticosteroids.
• Bronchodilators.
• Antihistamines. These medications might help if you have a mild allergic reaction or allergic rhinitis, rather than an asthma-related reaction.
• Vitamin B12. There’s some evidence that B12 might reduce your risk of an allergic reaction to sulfites.

How do I avoid foods that contain sulfites?

If you have a sulfite allergy or sensitivity, you’ll want to avoid the things that could trigger it. This is very similar to learning to avoid other allergens or irritants if you have asthma. Many countries require labels on foods, drinks and medicines that contain sulfites. You can also check for these sulfite-containing ingredients:

• Sulfur dioxide.
• Potassium bisulfite.
• Potassium metabisulfite.
• Sodium bisulfite.
• Sodium metabisulfite.
• Sodium sulfite.

What foods are high in sulfites?

Common foods that have high or moderate amounts of sulfites include:

• Beer.
• Wine.
• Some dried fruits.
• Lemon juice.
• Molasses.
• Sauerkraut.
• Gravies and sauces.
• Soft drinks, fruit juices and other nonalcoholic beverages.
• Dried potatoes.
• Shrimp, lobster and other crustaceans.
• Food made with dough, like biscuits, pie and pizza crusts.

The Food and Drug Administration (FDA) in the U.S. banned the use of sulfites in fresh fruits and vegetables in the 1980s.

Sulfites in medications

Medications that contain sulfites include:

• Epinephrine (adrenaline), norepinephrine (noradrenaline) and similar medications. This includes some dental anesthetics.
• Dexamethasone and some other corticosteroids. This includes creams and injectable corticosteroids.
• Topical antifungals.
• Dopamine.
• Aminoglycoside antibiotics.
• Doxycycline.
• Propofol.
• Topical anesthetics.

What can I expect if I have a sulfite sensitivity?

If you have a sulfite allergy or if sulfites make your asthma worse, you’ll probably need to take steps to avoid foods, drinks and medications that have high levels of them. Like any other allergy or asthma trigger, you’ll need to be prepared with medications in case you accidentally come in contact with sulfites.

When should I see my healthcare provider?

See a healthcare provider if you feel like your allergies or asthma aren’t well-managed. They can help you identify and avoid triggers.

When should I go to the ER?

Call 911 (or your local emergency service number) or go to the nearest emergency room if you’re having an asthma attack that’s not responding to medications or if you have signs of a severe allergic reaction, including:

• Trouble breathing or swallowing.
• Swelling of your lips, tongue, face or throat.
• Fast heart rate.
• Feeling weak or dizzy.
• Losing consciousness.

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

• How can I avoid reacting to sulfites?
• What foods, drinks and medications should I avoid?
• What alternatives are there for medications with sulfites in them?
• What symptoms should I look out for?
• What should I do if I have a reaction?
• When should I go to the ER?
• When should I follow up with you?