What you take for a food allergy depends entirely on how severe the reaction is. Mild symptoms like hives or an itchy mouth call for an over-the-counter antihistamine. A severe reaction involving breathing difficulty, throat swelling, or dizziness requires an epinephrine auto-injector immediately. Knowing which situation you’re in, and having the right medication on hand, can be the difference between a minor inconvenience and a medical emergency.
Mild Reactions: Antihistamines
For mild food allergy symptoms like hives, facial swelling, lip tingling, or an itchy mouth, an over-the-counter antihistamine is the standard treatment. Second-generation (non-drowsy) antihistamines are preferred because they don’t cross into the brain the way older antihistamines do, which means fewer side effects and no sedation. The most widely available options include cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra).
First-generation antihistamines like diphenhydramine (Benadryl) still work, but they cause significant drowsiness and interact with more medications. If you’re managing a mild reaction during the day or need to stay alert, a non-drowsy option is the better choice. Keep in mind that antihistamines take 15 to 30 minutes to start working, so they won’t stop a rapidly escalating reaction.
One important point: antihistamines only manage mild symptoms. They are not a substitute for epinephrine during a severe reaction. Swapping one for the other in a crisis is a dangerous and common mistake.
Severe Reactions: Epinephrine
Epinephrine is the only first-line treatment for anaphylaxis. If you experience any one of the following after eating a trigger food, use your auto-injector without hesitation:
- Difficult or noisy breathing
- Swelling of the tongue or tightness in the throat
- Wheezing or a persistent cough
- Difficulty talking or a hoarse voice
- Persistent dizziness or collapse
Anaphylaxis can happen without any skin symptoms at all. You don’t need to see hives before using epinephrine. The standard adult dose is 0.3 to 0.5 mg injected into the outer thigh. For children, dosing is based on weight at 0.01 mg per kilogram. Auto-injectors like EpiPen come in pre-measured doses, so you don’t need to calculate in the moment.
Delayed use of epinephrine is consistently linked to fatal outcomes in anaphylaxis cases. If you’re unsure whether a reaction is severe enough, the guidance from allergy organizations is clear: when in doubt, use it. The risks of giving epinephrine when it turns out not to be necessary are far smaller than the risks of waiting too long.
Stomach Symptoms: H2 Blockers
Food allergy reactions sometimes hit the gut hardest, causing nausea, cramping, or vomiting. While antihistamines target the histamine receptors responsible for skin and respiratory symptoms, a different class of medication targets histamine receptors in the stomach lining. These are called H2 blockers, and the most common one is famotidine (Pepcid).
H2 blockers are sometimes used alongside a standard antihistamine to provide broader coverage during a mild to moderate reaction. They’re available over the counter and are generally well tolerated. This combination, a regular antihistamine plus an H2 blocker, is a strategy some allergists recommend keeping in your action plan for reactions that involve significant GI distress.
What About Steroids?
Corticosteroids (like prednisone) have long been given after allergic reactions with the idea of preventing a “biphasic reaction,” a second wave of symptoms that can occur hours after the initial episode. However, the evidence for this practice is weak. A large study of over 31,000 hospitalized anaphylaxis patients in Japan found no significant difference in biphasic reaction rates between those who received corticosteroids and those who didn’t (10.7% vs. 10.5%).
Some emergency departments still prescribe a short course of oral steroids after a severe reaction, but routine use specifically to prevent a second wave doesn’t appear to be justified by current data. If you’re sent home with a steroid prescription after an ER visit, it’s worth discussing the reasoning with your allergist at your follow-up.
Longer-Term Options: Oral Immunotherapy
If you’re looking beyond treating reactions as they happen, oral immunotherapy (OIT) is a structured treatment that gradually builds tolerance to a specific food allergen. The FDA-approved peanut allergy treatment, Palforzia, works by exposing the immune system to tiny, increasing doses of peanut protein over many months. The process has three phases: an initial dose given in a clinical setting, an up-dosing period lasting roughly 20 to 40 weeks with dose increases every two weeks, and then daily maintenance at 300 mg of peanut protein.
In clinical trials, about 67% of children aged 4 to 17 on Palforzia could tolerate 600 mg of peanut protein (roughly two peanuts) with only mild symptoms, compared to just 4% on placebo. The treatment doesn’t cure peanut allergy. It raises the threshold for a reaction, meaning accidental exposure to a small amount becomes less likely to trigger a serious episode. You still need to avoid the food and carry epinephrine.
OIT does come with side effects, particularly GI symptoms, and some patients struggle to tolerate it. Sublingual immunotherapy (SLIT) offers an alternative that delivers much smaller doses of allergen under the tongue. SLIT causes fewer systemic and GI side effects, though it historically produced more modest desensitization. Recent studies using higher-dose SLIT protocols for peanut allergy have shown results approaching those of OIT, and some allergists now use SLIT as a stepping stone before transitioning patients to OIT.
Injectable Treatment for Multiple Food Allergies
In February 2024, the FDA approved Xolair (omalizumab) as the first medication designed to reduce allergic reactions to multiple foods after accidental exposure. Unlike OIT, which targets one allergen at a time, Xolair works by blocking the antibody (IgE) that drives allergic reactions across the board. It’s approved for adults and children 1 year and older who have IgE-mediated food allergies.
The approval was based on a study of 168 people allergic to peanut and at least two other foods, including milk, egg, wheat, cashew, hazelnut, or walnut. Xolair is given as an injection, typically every two to four weeks. Like OIT, it doesn’t eliminate the allergy. It raises the amount of allergen your body can handle before reacting, providing a safety net against accidental exposures. You still need to avoid your trigger foods and carry epinephrine.
Building Your Action Plan
The most effective approach to food allergy is having the right medications ready before a reaction starts. At minimum, that means carrying a non-drowsy antihistamine for mild symptoms and an epinephrine auto-injector for anything more serious. Many allergists also recommend keeping an H2 blocker on hand for GI-heavy reactions.
Know your specific triggers through proper allergy testing. Reactions don’t always follow the same pattern: a mild response one time doesn’t guarantee the next exposure will be mild. Having a written action plan that spells out which symptoms call for which medication removes the guesswork in a stressful moment. Your plan should be clear enough that someone else, a partner, teacher, or coworker, could follow it if you’re unable to treat yourself.