Food reactions: allergy or intolerance?
Many people who think they are allergic to a food may actually be intolerant of it. Some of the symptoms of food intolerance and food allergies are similar, but the differences between the two are very important because food allergy reactions can be life-threatening.
Food allergy symptoms? A common example of a food intolerance involves lactose, which is an inability to digest milk sugar. The treatment of an intolerance—avoidance of the offending food—is the same, but the reaction is not dangerous.
Being allergic to a food may also result from being allergic to a similar protein found in pollens or latex. This is known as cross-reactivity and it occurs when the immune system thinks one protein is closely related to another. When foods are involved it is called Oral Allergy Syndrome.
Allergic reactions to food normally occur within minutes of eating the trigger food, though they can sometimes appear a few hours later. Symptoms of a food allergy rash include:
- Hives or red, itchy skin
- Stuffy or itchy nose, sneezing or itchy, teary eyes
- Vomiting, stomach cramps, or diarrhea
- Angioedema or swelling
In some cases, food allergies can cause a severe reaction called anaphylaxis. Signs of this reaction include:
- Hoarseness, throat tightness, or a lump in the throat
- Wheezing, chest tightness, or trouble breathing
- Tingling in the hands, feet, lips, or scalp
If you experience any of these symptoms, call 911 immediately.
Eight foods are responsible for the majority of food reactions:
- Tree nuts
- Sesame seeds
However, many other foods can cause allergic reactions.
Food allergies can develop at any age and food reactions may appear several minutes to several hours after eating. Keeping a diary of all foods eaten may be helpful in identifying patterns.
At VAA, we will take a thorough history of your reaction to food, decide if skin, blood, or both testing is necessary. Evaluate the data to decide on the best treatment plan for food allergy testing.
- Baked egg and baked milk food challenges for most egg and milk allergic patients. Recipes will be provided for the muffins and skin testing will be performed on the day of the challenge to the muffin.
- Early introduction of peanuts in infants who are at risk for food allergies.
- Discuss oral immunotherapy to peanut, tree nuts, milk, egg, and sesame seed
- Discuss ongoing treatment studies for infants with food allergies being performed at local academic institutions.
- Supervised food challenges are performed to accurately diagnose or rule out a true food allergy. Skin testing is performed on the day of every food challenge. If the skin testing is reassuring, the patient will be given increasing doses of the food at predetermined intervals and observed for a period of time after the last dose. The entire challenge can last anywhere from 3-5 hours so bring toys/books/games to keep you occupied. Patients must bring the food they are eating to the office on the day of a challenge.
If you have severe food allergies, you should wear a medical alert bracelet or tag and carry an epinephrine auto-injector at all times.
There is currently no cure for food allergies and strict avoidance of your allergen is essential to preventing serious health problems.
Egg allergy and Influenza vaccines
People with egg allergies were previously told to avoid the flu vaccine or have skin testing before getting the vaccine. Since the risk of an allergic reaction is so small, the Centers for Disease Control now recommends vaccination for all individuals with an egg allergy without the need for special testing.
Therefore, most people with egg allergies should be able to get the vaccine in their primary care physician’s office. However, if either your doctor or you are nervous about getting the vaccine, we are happy to give the vaccine in our office for the first time.
However, anyone with a history of an allergic reaction to the flu shot itself should be evaluated by an allergist before any further flu vaccines are given.