Good Medicine: The Growing Threat of Adult Food Allergies

For more than 33 million Americans, a routine meal can turn into a medical emergency in a matter of minutes. New data published by Food Allergy Research and Education (FARE) shows that such extreme reactions are no longer just a childhood problem. The vast majority of those affected are now adults, with cases jumping 50% since the 1990s. 

Experts blame a perfect storm of modern lifestyle changes for the spike: overuse of antibiotics, overconsumption of processed foods, hyper-hygienic living spaces, and increasing exposure to pollutants. Even more concerning, half of these incidents result in anaphylaxis — a life-threatening, whole-body allergic reaction that can occur with little warning, causing rapid respiratory and circulatory collapse, even death.

According to the United States Food and Drug Administration, 90% of all food allergies are caused by the “Big Nine,” with shellfish and milk being the most common culprits in adults. The complete list includes peanuts tree nuts (walnuts, hazelnuts, pistachios, pecans, almonds, cashews, and Brazil nuts); eggs; fish; soybeans; sesame seeds; and wheat. 

Starting in November 2026, New York — which ranks among the top five states for food allergy prevalence — will be the first state to mandate allergen-labeling on grab-and-go items like deli sandwiches and bakery items.

Allergic reactions occur when the immune system mistakenly identifies a harmless food protein as a threat. It responds by producing antibodies called Immunoglobulin E (IgE), which attach to a specific group of white blood corpuscles, called mast cells. When more of that protein is eaten, it binds to IgE already sitting on the mast cells, and acts like a key in a lock — prompting a massive histamine release and igniting an allergic reaction.

In less severe cases, symptoms typically emerge within 30 minutes of eating a trigger food (though sometimes it can take up to six hours). Common reactions range from hives and itchy eyes to a scratchy throat, facial swelling, and wheezing. Symptoms may also be localized to the lips and mouth. 

In contrast, anaphylactic reactions can occur within seconds or minutes of eating, resulting in a sudden drop in blood pressure, difficulty breathing, vomiting, or shock. Because severe anaphylaxis can be fatal, it requires immediate medical intervention.

Food allergies are more common in individuals with a personal or family history of eczema, asthma, or environmental allergies (such as dust or pollen). While it’s hard to predict how severe a given allergic reaction will be, key risk factors include consuming a large amount of the trigger food (especially if raw), drinking alcohol with the allergen, poorly controlled asthma, or any ongoing illness.

Severe food-related allergic reactions are a medical emergency: Call 911 or go to the hospital. Otherwise, if you suspect you have a food allergy, ask your primary care provider for an allergist referral. Because the exact food allergen can be hard to pinpoint, the specialist may ask you to keep a detailed food diary. (Reactions may occur after having eaten multiple foods at once, or after accidental cross-contamination while cooking.) The allergist typically orders a blood test to measure IgE antibodies against specific foods, or painless skin-prick tests, in which a tiny amount of allergen is lightly scratched into the skin to check for a reaction. If results are unclear, the specialist may conduct an oral food challenge test: Increasing amounts of a suspected trigger food are eaten over a few hours — under strict medical supervision — to confirm or exclude a reaction.

Itching and hives from mild food allergies can be managed by over-the-counter antihistamines, such as cetirizine (generic Zyrtec). Diphenhydramine (generic Benadryl) is no longer recommended due to side effects like drowsiness and confusion.

Epinephrine remains the only treatment for severe food allergies and anaphylaxis. Suffers should carry this highly portable, self-injectable prescription medication at all times. Store epinephrine at room temperature in an accessible spot, such as a medicine cabinet or kitchen cupboard. Never leave it in direct sunlight or in your vehicle. 

While antihistamines and epinephrine only treat symptoms after they occur, new treatments can significantly lower the risk of life-threatening allergic reactions before the exposure happens. Your allergist may prescribe omalizumab (Xolair), an injectable medication that targets and blocks IgE antibodies, providing protection against accidental exposure to multiple foods. Another option, immunotherapy, builds long-term tolerance by exposing patients to gradually increasing, minute amounts of a trigger food — either swallowed or placed under the tongue.  

The best way to prevent an allergic reaction is to vigilantly avoid food allergens. Check label ingredients on ready-to-eat meals; look for the words, “made on shared equipment,” or “may contain.” Be cautious at restaurants: Call ahead — even ask to speak to the chef — to make sure you avoid exposure. 

Dr. Mary Jenkins, a contributor to the Herald and member of its board of directors, retired after nearly 40 years as a family practice physician in New York state.