Food allergies affect millions of people worldwide. When the body mistakenly identifies a harmless food protein as a threat, it launches an immune response — producing antibodies and releasing histamines that can cause anything from mild hives to life-threatening anaphylaxis. But even if you're vigilant about avoiding your triggers, allergens have a way of showing up where you'd least expect them. Here are seven common traps to watch out for.
1 Not Checking Ingredients Closely Enough
It sounds obvious, but food allergens turn up in the most surprising places — especially when you're eating out or buying prepared foods. Traditional recipes from around the world often include ingredients that aren't immediately apparent.
When ordering food at a restaurant or deli, never hesitate to ask about every ingredient — even the ones that seem straightforward.
2 Overlooking Sauces and Seasonings
We tend to focus on the main dish while paying little attention to the sauce drizzled on top or the dressing tossed through a salad. This is where allergens love to hide.
Pesto, for instance, may look like a simple herb sauce, but it's traditionally prepared with pine nuts. Teriyaki and soy sauce typically contain wheat. And if fish is your allergen, keep in mind that classic Caesar dressing and Worcestershire sauce are both commonly made with anchovies.
At restaurants, ask for sauces and dressings on the side — or request a full ingredient list before ordering.
3 Confusing 'Lactose-Free' with 'Dairy-Free'
This is one of the most common — and potentially dangerous — mix-ups. Lactose intolerance means your body struggles to digest the sugar found in milk. A dairy allergy, on the other hand, is an immune reaction to milk proteins — and it can be severe.
Products labeled "lactose-free" have simply had the lactose removed or broken down. They can still contain milk proteins like casein and whey, which are the very substances that trigger an allergic reaction. Even products marked "dairy-free" may occasionally include milk-derived ingredients, so always read the full ingredient list.
4 Forgetting About Commercial Processing
The way food is manufactured can introduce allergens you'd never suspect. Canned tuna, for example, may be packed in soy-based broth or processed with a milk-based binding agent. Many packaged beef products and deli meats contain milk powder or milk protein as a binder or tenderizer.
On top of that, foods can become contaminated simply by being packaged in a shared facility. A bag of pretzels might be perfectly wheat-only by recipe — but if it was packaged on equipment that also processes peanuts, traces may remain.
Look for "may contain" or "processed in a facility that also handles..." warnings on packaging. These aren't required by law, but many manufacturers include them voluntarily.
5 Assuming Every Allergen Will Be Listed on the Label
In the United States, the FASTER Act requires that nine major allergens be clearly identified on food labels. These are the "big nine" that manufacturers must disclose:
The 9 Major Allergens (U.S. Labeling Law)
But what if your allergy falls outside this list? Certain ingredients can legally be grouped under vague terms like "flavors," "spices," or "artificial flavoring" without being individually named. If you're allergic to something less common — like mustard, celery, or lupin — you'll need to be extra cautious and contact manufacturers directly when in doubt.
6 Not Thinking Twice About Cocktails and Mocktails
You might be perfectly fine with alcohol itself, but that doesn't make every mixed drink safe. Several classic cocktails — including whiskey sours and gin fizzes — use raw egg whites to create the frothy foam on top. Other drinks may incorporate nut-based liqueurs, dairy cream, or soy-based ingredients.
This applies to mocktails too. Fancy non-alcoholic drinks can include surprising ingredients like almond milk, coconut cream, or flavored syrups that contain allergens. Always ask the bartender about every component before taking a sip of something new.
7 Forgetting That Allergens Can Transfer Through Close Contact
Here's one that catches many people off guard: you don't always have to eat the allergen yourself to have a reaction. Research published in 2023 found that food allergens can be passively transferred between people through saliva, blood, breast milk, and other bodily fluids.
This means a kiss from someone who recently ate peanut butter, or close physical contact with a partner who consumed shellfish, could potentially trigger an allergic response — even though you never touched the food yourself. If you or your child has a severe allergy, it's worth having a conversation with close family and friends about timing and hygiene after they consume known allergens.
The Bottom Line
Living with a food allergy means being attentive not only to what you eat, but to how food is prepared, labeled, processed, and even shared. Allergens have a talent for hiding in the most unlikely places — from a drizzle of sauce to a goodnight kiss.
The good news is that awareness goes a long way. By understanding where these hidden risks lie, you can make smarter choices and enjoy your meals with greater confidence.
The Golden Rule: When in doubt, leave it out.
