Everything You Should Know About Food Allergies
Food allergy or food intolerance affects nearly everyone at some point. When someone has an unpleasant reaction to something they ate, they often think that they have an allergy to the food. Food allergy is an abnormal response to food that is triggered by a specific reaction in the immune system and expressed by certain symptoms. Food intolerance is also an abnormal response to food. Its symptoms can resemble those of food allergies however food intolerance is fare more prevalent and is triggered by several different mechanisms that are distinct from the immunological reaction responsible for food allergy. Anyone with a food allergy must attempt to identify and prevent them because these reactions may cause devastating illness and potentially be fatal.
In adults, the most common foods that cause allergic reactions are shellfish, nuts from trees, eggs, and peanuts. In highly allergic people, even minuscule amounts of a food allergen may prompt an allergic reaction. Less sensitive people, however, may be able to tolerate small amounts of a food to which they are allergic. In children, the pattern is somewhat different and the most common foods that cause allergic reactions are eggs, milk, peanuts, and fruits, particularly tomatoes and strawberries. Children sometimes outgrow their allergies, but most adults do not lose theirs. Adults and children tend to react to certain foods, including peanuts, fish, or shrimp or foods that they eat more often.
Cross reactivity is the occurrence of allergic reactions to foods that are chemically or otherwise related to foods known to cause allergy in an individual. For someone who has a life threatening reaction to a certain food, their doctor will advise the patient to avoid that food, plus any related foods which may cause the same allergic reaction. The oral allergy syndrome is another type of cross reactivity, which is both interesting and distressing. This syndrome occurs in people who are highly sensitive to ragweed or birch pollen. During the seasons in which these allergens pollinate, the patient may find that when they attempt to eat certain fruits, a rapid onset of itching is experienced in the mouth and throat, causing the fruit to not be eaten. The symptoms of this allergy, which is caused simply by the direct contact of the food with the lining of the mouth and throat, resolve rapidly.
Diagnosing a food allergy can be a challenge for most doctors. First the doctor must determine if the patient is having an adverse reaction to specific foods. The doctor makes this assessment with the help of a detailed history from the patient, the patient's dietary diary, or an elimination diet. The doctor then confirms the diagnosis by the more objective skin tests, blood tests, or food challenges. The dietary history is the most important diagnostic tool. The physician interviews the patient to determine if the facts are consistent with a food allergy. If the patient's history, dietary diary, or elimination diet suggests that a specific food allergy is likely, the doctor will then use tests, such as skin tests, blood tests, and a food challenge, which can more objectively confirm an allergic response to food.
