Food allergies can be caused by a wide variety of foods, although the most common are cow's milk, hen's eggs, peanuts, tree nuts, fish and shellfish. Food allergies can cause many types of symptoms, from mild rashes to life-threatening anaphylaxis.
While about two percent of Americans are believed to be affected by food allergies, researchers have found there is no single method that has been shown to be the best way to diagnose the condition. A combination of clinical history and one of several tests, such as a skin prick test, are commonly used by physicians to diagnose food allergies.
The new study found that variation in the measures used to make the diagnosis is limiting advancements in how to best treat patients with the condition. The first critical look at the scientific literature published about food allergies was conducted by The Southern California Evidence-Based Practice Center based at the RAND Corporation and the VA Greater Los Angeles Healthcare System.
Although there have been some reports suggesting food allergies are increasing, the lack of high-quality research on the condition makes it impossible at this time to determine whether the incidence of food allergies is actually rising, according to researchers.
While the standard treatment for food allergies is to remove the suspected problem food from a person's diet, researchers say they found little research that establishes the validity of that approach. Testing the approach among people with potentially life-threatening allergies would be unethical, but such studies should be considered for people with lesser symptoms, such as skin rashes, in order to establish the net effect of potential benefits compared to potential harms, according to researchers.