Sulfite allergy is a high sensitivity to sulfite, a sulfur-based compound that occurs naturally in your body as well as foods like onions, cabbage, and apples. In people with sulfite allergy, the immune system overreacts when exposed to sulfite. This causes allergic reaction symptoms like wheezing, itching, and hives.

Sulfite allergy can affect anyone. However, it is more common in people with asthma. About 1% of the United States population is estimated to be hypersensitive to sulfite. About 5% of this group has asthma.

If you have a sulfite allergy and eat foods that contain sulfite, you may experience allergy symptoms like:

• Cough
• Wheezing
• Itching and swelling
• Hives
• Tingling sensation
• Chest tightness
• Shortness of breath
• Runny nose
• Watery eyes
• Digestive problems like vomiting and stomach cramps

Allergy vs. Sensitivity

While often used interchangeably, food sensitivity is not always the same as food allergy. Not all sulfite sensitivities are “true” allergies. A true allergy typically involves the immune system releasing an antibody (protein) called Immunoglobulin E (IgE). IgE travels to different cells, releasing chemicals that cause allergic reaction symptoms in the throat, lungs, nose, and skin.

There are cases of non-IgE-related sensitivities. These are not generally considered true allergies. Affected individuals are intolerant to sulfite. However, instead of releasing the IgE protein, their immune system releases other proteins, such as immunoglobulin G (IgG).

Both true allergies and hypersensitivities share similar symptoms and are often difficult to distinguish. However, true allergies tend to cause more severe symptoms, such as a sudden drop in blood pressure and breathing difficulty, that may lead to death. This is known as an anaphylactic reaction. Also, not everyone who develops IgE antibodies to sulfite would have an allergic reaction.

A sulfite allergy occurs due to an abnormal immune system response to sulfite, leading to a series of adverse reactions. Consuming foods high in sulfites can cause such reactions. Examples include:

• Wine and beer
• Lemon and lime juice
• Molasses
• Dried fruits
• Fermented foods

In the past, sulfites were often used to preserve foods and prevent browning in vegetables. However, in 1986, the U.S. Food and Drug Administration (FDA) banned the use of sulfites in fresh fruits and vegetables due to increased reports of allergic or allergy-type reactions.

Exposure to sulfites can also occur from the use of sulfite-containing cosmetic products like creams and body washes. Sulfite is also found in some compounded drugs.

Note: Sulfite allergy is not the same as sulfa allergy. Sulfa allergy is when you react to substances that contain sulfonamide molecules. This is not the same as sulfites, and their chemical structures differ.

Examples of specific sulfites that may cause allergic reactions include:

• Potassium metabisulfite
• Sodium bisulfite
• Potassium bisulfite
• Sodium sulfite
• Sodium metabisulfite

Health experts are not sure why some people develop an allergy to a specific substance. However, certain factors can increase the risk.

Risk Factors

Factors that can increase the risk of allergy to substances like sulfite include:

• Genes: Genetics may influence the development of sulfite allergy, as the increased chances of having allergies tend to run in families. This is called atopy.
• Environmental factors: Environmental factors may also be linked to allergies. For instance, people who smoke or are exposed to polluted air may be at a higher risk of having allergic diseases.
• Dietary habits: Some studies suggest there may be a link between allergy development and what you eat or your eating habits. For instance, smoking tobacco, eating meals high in calories, and eating late at night might increase allergy risk.
• Certain medical conditions: People with health conditions like eczema and respiratory infections may be more sensitive to allergens. According to the National Institute of Allergy and Infectious Diseases, eczema is one of the biggest risk factors for food allergies.
  

Healthcare providers currently do not have a standard protocol for diagnosing sulfite allergy. In some cases, they may order a blood test to determine the presence and level of IgE antibody to sulfite in your blood.

However, most sulfite sensitivities are not true allergies involving IgE. This means a blood test may not detect the presence of this antibody. And even if it does, it does not necessarily mean you have an allergy.

Oral challenge tests have also been widely used in diagnosing this condition. This test is usually done in the hospital under the care of your healthcare team. It involves ingesting food or fluid with increasing amounts of sulfite, during which time you are carefully assessed to look for symptoms of allergy.

Your healthcare provider may also suggest you keep a food journal. You would record each food you eat that caused any adverse reaction and the specific reactions you experienced. This can help your doctor make a diagnosis.

The main way to manage sulfite allergy is to avoid eating foods or using medicines that contain sulfites. If you are allergic to sulfite and get exposed to it, treatment options are available to curb attacks and manage symptoms. These may include:

• Corticosteroids: These are a form of steroids that are effective in treating allergic conditions. They relieve swelling and itchiness and stop severe reactions. They can be prescribed in various forms, such as creams or ointments, pills, liquid, and nose sprays.
• Antihistamines: These block the action of histamine, a chemical that causes allergy symptoms. They relieve symptoms like an itchy and runny nose, skin rashes, hives, and watery eyes. Your healthcare provider can prescribe antihistamines in the form of capsules, tablets, liquids, eye drops, nasal sprays, and injections.
• Decongestants: These medications relieve a congested nose. Your healthcare provider will give you guidelines on how to use them.
• Epinephrine: This is a human-made version of the hormone epinephrine. It is an emergency, life-saving medication that can stop or delay a severe allergic reaction. It is injected using the EpiPen. Seek medical care after using an EpiPen, as the effects may only be temporary.
  

There is no sure way to prevent the development of allergies. However, you can avoid your trigger, which in this case is sulfite-containing foods, to prevent attacks.

The FDA requires that food manufacturing companies show on their product label if their foods have greater than 10 parts per million (ppm) of sulfites. If you are sensitive to sulfites, check nutrition labels when grocery shopping. Look out for ingredients bearing specific sulfite names like sodium bisulfite and sodium sulfite.

Choose foods with no or very low sulfite levels, such as fresh meat and fish, fresh produce, dairy, and grains. Avoid medicines that contain sulfites. Your healthcare provider can give you more detailed information about specific medications to avoid.

Also, early research suggests that giving infants allergy-causing foods, including peanuts and milk, may help prevent food allergies from developing. This may apply to other potential allergens in food, like sulfites. However, more research is needed.

If left unmanaged, a sulfite allergy attack can cause or worsen severe health issues, such as:

• Dermatitis: This is the skin’s reaction to an allergen or irritant. A typical symptom is itchy and swollen rashes.
• Anaphylactic shock: This is a life-threatening event that happens very quickly. The immune system releases a flood of chemicals that can cause symptoms like narrowing of the airways and difficulty breathing. This can cause you to go into shock.
• Urticaria (hives): This is the appearance of itchy, red bumps on the skin. They can occur within one to two hours after you are exposed to an allergen and may resolve after about eight hours.
• Hypotension (low blood pressure): This is a sudden drop in blood pressure below 90/60 millimeters of mercury (mm Hg). This can happen during an anaphylactic attack. If not managed, it can lead to organ failure and death.
• Angioderma (deep swelling): This occurs when there is a buildup of fluid on the skin. It causes swelling of the deeper layers of the skin.
  

Sulfite allergy occurs when the body overreacts to consumed or inhaled sulfite. Sulfites occur naturally in the body and in some foods. They are also commercially produced and added to foods, cosmetic products, and some medicines.

Sulfite allergy can cause symptoms like rashes, itchiness, coughing, and watery eyes. Though not common, severe cases can cause more serious symptoms, including difficulty breathing and shock. There is no standard method of diagnosis for this allergy. However, working with a healthcare team helps ensure proper diagnosis and treatment.