Sulfites and Your Skin: The Secret Trigger Behind Rashes and Reactions

Victoria Asuquo, MD Candidate

Founder, Beneath the Surface

What Are Sulfites?

Sulfites are chemical compounds that release sulfur dioxide, a gas that acts as a powerful antioxidant and antimicrobial. They're used to preserve the color, flavor, and freshness of foods such as fruit juices, seafood, baked goods, and alcoholic beverages. Sulfites also occur naturally through the fermentation process, especially in wine and beer.

Though sulfites have been approved for use by the FDA, any food or drink that contains 10 parts per million (ppm) or more must be labeled accordingly. However, labeling doesn't always guarantee safety, particularly for individuals with sulfite sensitivity.

Sulfite Sensitivity: More Than a Food Allergy

For some individuals, exposure to sulfites can lead to a range of adverse reactions including wheezing, chest tightness, coughing, and even life-threatening bronchospasms, especially in people with asthma. Others may experience skin-related symptoms such as urticaria (hives) or angioedema (swelling).

Sulfite sensitivity can develop at any point in a person's life and is not routinely included in standard allergen testing in the United States. In contrast, screening panels in Europe and by the North American Contact Dermatitis Group (NACDG) include sulfites, specifically metabisulfite, in their patch test series. This omission in U.S. testing protocols raises concern, especially given the rising rates of contact dermatitis in the general population.

In fact, the American Contact Dermatitis Society (ACDS) named sulfites the "Allergen of the Year" for 2024 to highlight this exact gap in dermatologic care and encourage more comprehensive screening.

Testing Sulfites in Everyday Beverages

To better understand sulfite exposure in common consumer products, researchers are using practical tools such as sulfite test strips to analyze beverage samples. These strips react with sulfites in a drink, changing color to indicate concentration levels, usually ranging from 10 mg/L to 500 mg/L.

For example:

• Wine can contain up to 350 mg/L of sulfites.
• Beer generally falls in the 10–50 mg/L range.
• Fruit juices and sodas may also contain sulfites, depending on the brand and preservatives used.

While not as precise as laboratory methods like the Monier-Williams distillation-titration, test strips offer an accessible and cost-effective way to estimate sulfite levels, especially for research, public health studies, and consumer awareness.

Why This Matters for Dermatology

The growing use of sulfites across industries, combined with their omission from common allergen tests, presents a challenge for dermatologists trying to diagnose unexplained cases of contact dermatitis. Patients may react to products they consume or touch regularly, yet without sulfites on the patch test panel, the true allergen may go unnoticed.

Adding sulfites to standard testing panels could improve diagnosis and treatment for many patients. Until then, healthcare professionals and consumers alike need to remain vigilant.

Moving Forward

Sulfites are everywhere, from our grocery store shelves to our medicine cabinets. For individuals with sensitivities, exposure can lead to more than just mild discomfort. It can result in serious dermatologic and respiratory reactions that affect quality of life.

Raising awareness, improving testing standards, and conducting continued research into everyday exposure will be key steps in ensuring better care, especially as we strive to provide more personalized and inclusive dermatologic treatment.