Food Allergy or Intolerance? Here’s What to Do Next

From the growing prevalence of gluten-free options and dairy alternatives, it should be no surprise that food allergies and intolerances are on the rise. A 2025 survey by the International Food Information Council found that over half of Americans either have, live with, or know someone affected by a food allergy, intolerance, or sensitivity. 

 

Yet as awareness grows, so does confusion. Not all reactions to food are the same and knowing what you’re dealing with matters. “There’s a broad spectrum—from true allergies to sensitivities to intolerances,” says Dr. Elizabeth Ender, allergist at Aspirus St. Luke’s. “It can be tricky to distinguish between them and knowing what’s going on with your body will affect how you respond to it.” 

 

A true food allergy triggers a full-on immune response. These reactions can be serious—even life-threatening—with symptoms that appear quickly, like hives, swelling, wheezing, vomiting, or anaphylaxis. The most common food allergens in the US include milk, eggs, wheat, soy, tree nuts, peanuts, sesame, fish, and shellfish. 

 

In contrast, food intolerances can happen when the body has trouble digesting certain food components, causing bloating, gas, or stomach cramps. Common examples are lactose intolerance, gluten intolerance (non-celiac), and fructose intolerance.   

 

Food sensitivities are the hardest to identify. They can cause symptoms such as headaches, fatigue, eczema flare-ups, or brain fog without known involvement of the immune system or digestive enzymes. People may react to additives, natural compounds like salicylates (found in fruits, vegetables, and spices), or FODMAPs—fermentable short-chain carbs that trigger symptoms in sensitive individuals.   

 

“Treatment depends on what kind of reaction your body is having,” says Dr. Ender. “True allergies require strict avoidance and often an EpiPen to treat serious reactions. Intolerances and sensitivities can usually be managed by adjusting your diet or using enzyme supplements like Lactaid. But unnecessarily cutting out foods can cause nutritional gaps and stress. That’s why a proper diagnosis and guidance from a health professional really matter.”   

 

Although home testing kits for food sensitivities are widely advertised, many lack scientific backing and can lead to misleading results. “The gold standard for diagnosis is still an oral food challenge, done under medical supervision,” says Dr. Ender. 

 

If you suspect a food allergy, intolerance, or sensitivity, starting a detailed food and symptom journal is one of the best things you can do. Write down what you eat, note when symptoms appear, and describe their intensity and duration. Over days or weeks, this record reveals patterns and triggers you might otherwise miss. 

 

This information isn’t just helpful for you—it will provide invaluable data for your health care team. This will enable them to accurately diagnose your condition and tailor a treatment plan.  

 

Managing food reactions takes effort, but the tools and support available today are better than ever. “It can feel very scary to react to a food,” says Dr. Ender. "But every year we have more knowledge and more options to help prevent and treat food allergies, and we're here to help you figure out what is going on." 

 

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