Content Reviewers:Rishi Desai, MD, MPH
It’s different from food intolerances because it involves the immune system.
Now, any food can cause allergies. But, the most common are the big eight: milk; eggs; peanuts; tree nuts, like almonds, walnuts, and pecans; seafood, like bass, flounder, and cod; shellfish, like crabs, lobster, and shrimp; soy; and wheat.
Now, normally food doesn’t cause an allergic reaction.
But a food allergy can develop in two steps; a first exposure; and then a second exposure later, which usually is a lot more serious.
So, let’s say a person eats shrimp for the first time, and for some reason has an immune response where antibodies are produced in his body that specifically recognize shrimp as a bad actor, called an allergen.
These shrimp-specific antibodies then stay in the body and lay around, looking out for shrimp.
If that same person has a second exposure to shrimp, maybe even months later, the shrimp-specific antibodies spot the shrimp and cause the immune system to leap into action, releasing a bunch of molecules in the body which cause many of the symptoms of an allergic reaction.
A life-threatening reaction, called anaphylaxis, can develop minutes to hours after even a very small second exposure to the food allergen, even if it is just breathing in allergen dust or contacting a contaminated surface.
And while symptoms can vary between people and reactions, they can include minor skin rash or hives, to more serious symptoms like itching, swelling or tingling of the eyes, lips, tongue, mouth or throat; vomiting; diarrhea; stomach cramps; dizziness and fainting; plus wheezing, coughing, and difficulty breathing.
Sometimes symptoms can improve for a bit, but then get worse again over a few hours.
With every re-exposure to the food allergen, the reaction can get even more severe and in some cases be life threatening.
Early recognition and management of allergic reactions to food are really important to prevent serious health consequences; and the main, immediate treatment for anaphylaxis is an epinephrine auto injector called an EpiPen or EpiPen Jr. for kids.
The auto injector can be life-saving, so it’s important to read the instructions with the EpiPen and practice so you know how to use it.
EpiPens should be stored at room temperature and protected from light, and should be immediately replaced if expired.
Now, as soon as symptoms of anaphylaxis are suspected, remove the allergen and you or someone else needs to administer the EpiPen immediately.