A food allergy can be described the reaction of the immune
system to a harmless food as if it were a threat. While there are several types
of immune responses to food, we will focus on one specific type of reaction –
where the body produces a specific type of antibody call immunoglobulin E
(IgE). The binding of IgE to certain molecules in food triggers the immune
system to respond.
The first time a person eats the food, no symptoms may be
present. The first time they are exposed to that food, their immune system
reacts as if the food is harmful and makes specific IgE antibodies for that
allergen. The antibodies then circulate throughout the body and attach to
different tissues.
The next time they eat the food
an allergic reaction could happen. When ingested, the food allergen binds to
the IgE antibodies that have attached throughout the body, releasing massive
amounts of chemicals such as histamine. Depending on the tissue where they are
released, the chemicals will cause various symptoms, ranging from mild to
severe. A severe allergic reaction can include anaphylaxis, a potentially
life-threating response.
Anaphylaxis may begin abruptly and could lead to death if
not treated immediately. This includes a wide range of symptoms that can
present themselves in many combinations. Some symptoms are not as dangerous,
but the most severe restrict breathing and circulation.
Affected areas could include:
SKIN: itching, hives, redness, swelling
NOSE: sneezing, stuffy nose, runny nose
MOUTH: itching, swelling of lips and tongue
THROAT: itching, tightness, difficulty swallowing,
hoarseness
CHEST: shortness of breath, cough, wheeze, chest pain,
tightness
HEART: weak pulse, passing out, shock
GI TRACT: vomiting, diarrhea, cramps
NERVOUS SYSTEM:
dizziness or fainting
Symptoms can begin immediately or several hours after
contact. Sometimes the symptoms go away, only to return 2 to 8 hours later. Anaphylaxis
is highly unpredictable, but if you begin to experience symptoms you must seek
medical attention immediately because it can be deadly.
Common Food Allergies
in Infant, Children and Adults
In infants and children:
In adults:
Food allergies usually develop at an early age but can
develop anytime. Children can outgrow egg, milk, and soy allergies. However, people
who develop allergies as usually adults have them for life.
