Symptoms of Allergic Reactions to Foods

Reference information: www.aaaai.org, www.allergy.hk

Symptoms of allergic reactions are generally seen on the skin (hives, itchiness, swelling of the skin). Gastrointestinal symptoms may include vomiting and diarrhea. Respiratory symptoms may accompany skin and gastrointestinal symptoms, but don't usually occur alone.

Severe Allergic Reactions

Anaphylaxis (pronounced an-a-fi-LAK-sis) is a serious allergic reaction that happens very quickly. Without immediate treatment-an injection of epinephrine (adrenalin) and expert care-anaphylaxis can be fatal. Follow-up care by an allergist/immunologist, often referred to as an allergist, is essential.

Symptoms of anaphylaxis may include difficulty breathing, dizziness or loss of consciousness. If you have any of these symptoms, particularly after eating, seek medical care immediately (call 999). Don't wait to see if your symptoms go away or get better on their own.

Diagnosis

An allergist is the best qualified professional to diagnose food allergy. Your allergist will take a thorough medical history, followed by a physical examination. You may be asked about contents of the foods, the frequency, seasonality, severity and nature of your symptoms and the amount of time between eating a food and any reaction.

Allergy skin tests may determine which foods, if any, trigger your allergic symptoms. In skin testing, a small amount of extract made from the food is placed on the back or arm. If a raised bump or small hive develops within 20 minutes, it indicates a possible allergy. If it does not develop, the test is negative. It is uncommon for someone with a negative skin test to have an IgE-mediated food allergy.

In certain cases, such as in patients with severe eczema, an allergy skin test cannot be done. Your physician may recommend a blood test. False positive results may occur with both skin and blood testing. Food challenges are often required to confirm the diagnosis. Food challenges are done by consuming the food in a medical setting to determine if that food causes a reaction.

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.