Eating a balanced diet with plenty of fruits and vegetables is one way doctors recommend to maintain a healthy lifestyle. But what if every time certain fruits and vegetables are eaten, one develops a sore throat, swollen tongue, itchy mouth, or itchy lips? Joseph R. Perez, M.D., a board-certified allergist and immunologist in Houston, Texas (www.aachou.com), says that this condition is known as oral allergy syndrome (OAS). "Many people who suffer from seasonal allergies don't even realize that itching of the mouth, tongue, or throat after eating fresh fruits or vegetables can be related to allergies of the nose or lungs", says Dr. Perez.

A new study published in the Journal of Allergy and Clinical Immunology states that this happens in about 25% of people with seasonal allergy problems such as ragweed allergy. The study reports that oral itching during ragweed season may be the first sign that one will develop OAS. Ragweed season typically starts in mid-August and can persist throughout the entire fall season.
   
OAS occurs because certain allergy proteins are common or similar between plant pollens and certain fruits or vegetables. Dr. Perez says that fresh fruits and vegetables are more likely to cause oral symptoms but the problem can be present even with cooked fruits and vegetables. "People who are sensitive to ragweed allergen may also have a problem eating melons, bananas, cucumber, zucchini, Echinacea, or chamomile tea", notes Dr. Perez.

The danger lies with severe symptoms associated with ingestion of fruits and vegetables. OAS can sometimes be severe enough to cause throat swelling or systemic reactions leading to emergency room visits.

The American Academy of Allergy, Asthma, and Immunology says that patients should see an allergist/immunologist if they:

• Experience itchy mouth from raw fruits or vegetables
• Have limited their diet based upon perceived adverse reactions to foods or additives
• Have prolonged or severe symptoms of rhinitis
• Have nasal polyps
• Have co-existing conditions such as asthma or recurrent sinusitis
• Have symptoms interfering with quality of life and/or ability to function
• Have found medications to be ineffective or have had adverse reactions to medications
• Are a child with allergic rhinitis, because immunotherapy may potentially prevent the development of asthma