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.
Eight foods are responsible for the majority of allergic reactions:
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.
With a true food allergy, an individual’s immune system will overreact to an ordinarily harmless food. This is caused by an allergic antibody called IgE (Immunoglobulin E), which is found in people with allergies. This antibody may develop after eating the food repeatedly in the past but without having problems. Food allergy may appear more often in someone who has family members with allergies and symptoms may occur after that allergic individual consumes even a tiny amount of the food.
Being allergic to a food may also result in being allergic to a similar protein found in something else. For example, if you are allergic to ragweed, you may also develop reactions to bananas or melons. This is known as cross-reactivity. Cross-reactivity happens when the immune system thinks one protein is closely related to another. When foods are involved it is called oral allergy syndrome (OAS).
Food intolerance is sometimes confused with food allergy. Food intolerance refers to an abnormal response to a food or food additive that is not an allergic reaction. It differs from an allergy in that it does not involve the immune system. For instance, an individual may have uncomfortable abdominal symptoms after consuming milk. This reaction is most likely caused by milk sugar (lactose) intolerance, in which the individual lacks the enzymes to break down milk sugar for proper digestion. Dr. Sim can help determine the difference between intolerance and allergy and help establish a management plan.
Food allergy can affect children and adults alike. While many children outgrow a food allergy, it is also possible for adults to develop allergies to particular foods.
Symptoms of food allergy
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:
In some cases, food allergies can cause a severe reaction called anaphylaxis. Signs of this reaction include:
If you experience any of these symptoms, call 911 immediately.
Proper diagnosis of food allergies is extremely important. Studies have shown that many suspected food allergies are actually caused by other conditions such as a food intolerance. Skin tests and blood tests are often ordered.
A good resource for patients and parents of children with food allergies:
FARE (Food Allery Research & Education) https://www.foodallergy.org/