How Long Does a Food Allergy Reaction Last? (2024)

FAQs

How Long Does a Food Allergy Reaction Last? ›

Allergies can take a few hours to even days to subside. However, food allergies are generally not very serious and usually resolve in a few minutes to hours. Some common foods that can trigger an allergic response are peanuts, fish, wheat, milk, eggs, or shellfish.

Symptoms usually start as soon as a few minutes after eating a food and as long as two hours after. In some cases, after the first symptoms go away, a second wave of symptoms comes back one to four hours later (or sometimes even longer). This second wave is called a biphasic reaction.

Some allergic reactions may take two to four weeks to resolve, even with appropriate treatment. Mild allergic reactions, such as hives, hay fever, or nasal congestion, may resolve within a few hours to a day either with treatment such as medication or allergy shots or subside naturally.

Egg, milk, soy and wheat allergies are the ones we usually see being outgrown. About 80 percent of people with egg, milk and wheat allergies outgrow them, usually by age 16. About 20 to 25 percent of children with peanut allergies outgrow them, and about 80 percent who outgrow them will do so by age 8.

Fast Facts About Food Challenge Testing

The test is done at the doctor's office or the hospital in case an allergic reaction takes place. Food challenge testing may take an entire day, but typically it takes about 3 or 4 hours.

Food allergies typically clear from your system within 24 to 72 hours. Reactions to certain foods might appear immediately or up to two hours after consumption. However, for severe allergies, it's important to consult with a healthcare professional for individualized advice.

If symptoms are severe, that means administering epinephrine. There is no way to flush food allergens out of your system. Rather, you need to avoid ingesting the food that triggers your allergy. And if severe symptoms occur, you need to treat the symptoms, with epinephrine.

Allergies occur at the same time every year and last as long as the allergen is in the air (usually 2-3 weeks per allergen). Allergies cause itching of the nose and eyes along with other nasal symptoms. Colds last about one week and have less itching of the nose and eyes.

This causes the symptoms of an allergic reaction. This typically occurs quickly, within minutes to two hours after eating. A person with a food allergy may also have a "local reaction" if the food touches their skin (hives or a rash at the site of contact), even if they don't actually eat it.

Use an over-the-counter antihistamine, such as diphenhydramine (Benadryl) or loratadine (Claritin), to treat mild symptoms. Read and follow all instructions on the label. Mild symptoms include sneezing or an itchy or runny nose; an itchy mouth; a few hives or mild itching; and mild nausea or stomach discomfort.

How long does it take to recover from food intolerance? ›

In people with a food intolerance, the amount of that food they eat determines the severity of their symptoms. The symptoms of food intolerances can take a while to emerge. The onset may occur several hours after ingesting a food, and the symptoms may persist for several hours or days.

Oral immunotherapy, or OIT, helps desensitize patients to the foods they are allergic to by giving them small quantities of the food allergen to ingest every day and gradually building their body's resistance to the food.

Use an over-the-counter antihistamine, such as diphenhydramine (Benadryl) or loratadine (Claritin), to treat mild symptoms. Read and follow all instructions on the label. Mild symptoms include sneezing or an itchy or runny nose; an itchy mouth; a few hives or mild itching; and mild nausea or stomach discomfort.

Delayed reactions occur from hours to days after eating the offending food. Symptoms may include vomiting, pain, diarrhea, blood stools, or poor growth. Some children may have hives or eczema. Delayed reactions are the most common form of food allergy.