Testing Food Allergies How to Suspect, Test and Avoid
Approximately 2% of adults and 8% of children usually suffer from many kinds of food allergies. When spoilt or improper food has been eaten, the organism will react in minutes inallergies.
The most commonsymptomsof food allergies are:
skin: itching, urticaria, angioedema
nasal reactions: sneezing, running nose, itchy eyes and nose
gastrointestinal symptoms: vomiting, nausea, diarrhea, cramping
lung disorder: shortness of breath, coughing, wheezing, chest tightness
vascular system: low blood pressure, rapid heart beat, light dizziness
It is important to know that anaphylaxis is a life threatening reaction.
Mostfood reactionsare not allergic at all, but they take place while being intolerant and sensitive to particular foods. There is no allergic antibody in a human organism to prevent any food disorder in a person. That is simply intolerance to cause allergy, thus, it can be classified as toxic (alcohol, caffeine or any case of food-poisoning) and non-toxic (eating lactose-containing foods - dairy foods, for example).
Less commonformsof non-allergic food reactions involve the immune system. They take place in children (milk, cereal grains, wheat, soy, eggs, nuts, fish and shellfish).
Cross-reactivity refers to persons having allergies to similar foods within one food group (if a person is allergic to nuts, he or she is obviously allergic to all tree-nuts, such as walnuts, almonds and cashews).
Cross-contamination refers to a "hidden allergy". For example, peanuts and tree nuts are not related foods, but both can be the reason of a food allergy.
Individual history of a specific food reaction and positive result of allergic antibody against that food help to diagnose a certain food allergy.
Allergy testscan define the substances which cause a personal allergy.
There are many methods of allergy testing. The most common are:
blood tests (RAST test - radioallergosorbent test)
Apricktestneeds a small amount of suspected allergy-causing substance to place on the skin (forearm, upper arm, back), and it is pricked to make the allergen go under the surface. The results are usually seen in 15-20 minutes, and show swelling or reddening. Several allergens can be tested simultaneously.
Anintradermal skin testis a similar method. It is used to test some specific allergen, such as penicillin or bee venom. An injection of a small allergen portion is made into the skin to get a site reaction.
Patch testingdiagnoses possible allergens in 48 hours.
An elimination diet may check any food allergy. The foods that may cause the symptoms are removed from the diet for a few weeks, and then one of them is slowly re-introduced. The signs of any allergic reaction will be seen soon.
Blood tests measure the amount of immunoglobulin (IgE antibodies) in a specific blood allergen. This test is performed if no skin testing is helpful or can be done at all.
Provocation or challenge testing involves a person into taking a suspected allergen but under control (the diet or breathing in the allergen). Severe allergic reactions may be provoked, so this type of testing should be done only if a doctor allows.
This method means to give some disguised food or harmless substances. Neither a tested person nor a provider knows whether the tested substance or food does any harm. This is some sort of a code to identify the reason. A number of sessions are required if several substances are used during investigation.
A double-blind strategy must be done carefully. It is practiced for mild allergic reactions, but blood tests may be the first safe approach.
How to get prepared for the food allergy testing
Before any food allergies testing, the patient must be asked about his/her medical history details: illnesses, work, entertainment, emotional and social conditions, lifestyle, eating habits and food.
No antihistamines or any other medicine are to be taken before skin testing, as this may lead to a negative result or reveal severe allergic reaction.
How a person may feel after testing food allergies
Skin testing may cause a slight discomfort while pricking and itching if a patient has got a positive reaction to the allergen.
Conclusion: food allergy testing is performed to determine health problems in order to solve them as quickly as possible.