Food Allergy

Food Allergy

If you have a food allergy, your immune system overreacts to a particular protein found in that food. Symptoms can occur when coming in contact with just a tiny amount of the food.

Many food allergies are first diagnosed in young children, though they may also appear in older children and adults.  Food Allergies are a growing concern especially in the pediatric population. The prevalence of food allergies in children under age 2 is nearly 6-8% and falls progressively with time to 3% of the general population.  While food allergy does occur in adults, it is much less common.  

Common childhood food allergies include:  milk, egg, wheat, soy, peanuts and nuts.

Common adult food allergies are: peanut, tree nut and seafood, especially shrimp.

The good news for most children with milk and egg allergy is that 70-80% of them will outgrow these allergies with time.

The news is not as good for peanut allergy. Only 20%, (usually infants who develop peanut allergy) will become tolerant with time. Very few adults who develop allergy to tree nuts, peanuts or seafood become tolerant.

Many people who think they are allergic to a food may actually be intolerant to it. Some of the symptoms of food intolerance and food allergy are similar, but the differences between the two are very important. If you are allergic to a food, this allergen triggers a response in the immune system. Food allergy reactions can be life-threatening, so people with this type of allergy must be very careful to avoid their food triggers.

A visit to an allergist can help you differentiate the two and diagnose the culprit foods causing your reactions.

Food Allergy Symptoms & Diagnosis

Symptoms
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 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.

Why do I have food allergy?
If your parents or siblings have food allergies you are at increased risk (about 75%) of having or developing a food allergy.

Which foods are most likely to cause allergy?
Eight foods are responsible for the majority of allergic reactions:
•    Cow’s milk
•    Eggs
•    Fish
•    Peanuts
•    Shellfish
•    Soy
•    Tree nuts
•    Wheat

For additional resources on food allergies, visit the Food Allergy and Anaphylaxis Network.  For the Guidelines for the Diagnosis and Management of Food Allergy in the United States visit the National Institute of Allergy and Infectious Diseases.

Why is it Important to Diagnose a Food Allergy?
The food that caused the reaction may not be obvious. Therefore, at Breathe Easy Allergy & Asthma Clinic, we use allergy skin testing and CAP RAST (blood tests) to evaluate patients.

Allergy skin testing is the most accurate and preferred method of evaluating allergies. These tests are safe, minimally invasive, and easily interpreted. Blood assays or RAST may present the clinician with diagnostic challenges. Studies have shown variability between different labs so that results can be difficult to interpret.

Blood tests also have decreased sensitivity compared to skin testing. Results from blood tests can often take a week or longer to be reported.

There are times when an oral food challenge is performed to confirm a specific food allergy diagnosis.   Board-certified allergists are the only physicians with specialized training in food allergy.

Food Allergy Treatment & Management
Proper diagnosis of food allergy or food intolerance by an allergist / immunologist is the first step to managing your condition.

If you are diagnosed with a food allergy, the treatment plan will be to strictly avoid that food. If you are diagnosed with an intolerance, you may be able to ingest small quantities without having a reaction.

There is currently no cure for food allergies; nor are there medicines to prevent reactions. Yet there are steps you should take to manage your condition. The most important of these is avoiding coming in contact with food proteins that can cause an allergic reaction.  There are treatment strategies under research, but these have not gained FDA approval yet.  

Read food labels to ensure that you don’t eat foods that contain foods to which you are allergic. Always ask about ingredients when eating at restaurants or when you are eating foods prepared by family or friends.

If you have severe allergies to food, be sure to complete an Anaphylaxis Action Plan and carry your autoinjectable epinephrine with you at all times. Use this medication in the event of an anaphylactic reaction.

For milder reactions, antihistamines may help relieve symptoms. Be sure to discuss this approach with your allergist / immunologist.

Food allergies can be confusing and isolating. Contact the Food Allergy & Anaphylaxis Network (FAAN) for patient support.

The Guidelines for the Diagnosis and Management of Food Allergy in the United States: Summary for Patients, Families, and Caregivers.