Determining which food is the cause of an allergic reaction is the key to treatment. Before you identify the culinary culprit you must consider what type of food allergy your patient has. There are two types of food allergies. They are classified as:

• Fixed food allergies: A fixed food allergy may be very apparent, such as the child whose lips swell and throat itches immediately in response to eating peanuts. The cause for this type of food allergy is similar to that of inhalant allergies, so the diagnosis is more easily reached. Blood testing (i.e., RAST test) is typically used to verify fixed food allergies. Approximately five to 15 percent of food allergies are of the fixed variety.

• Cyclic food allergies: These allergies are far more common but less understood. Delayed food allergy symptoms can take up to three days to appear. This type of reaction is associated with the body’s immunoglobin G (IgG) or antibodies. Unlike fixed food allergies, this allergic response is cyclical in nature. As an example, a child may be IgG sensitive to milk. Consequently, symptoms might appear if the child increases the intake and/or frequency of milk consumption.