A tomato allergy is rare but troublesome. Tomatoes are in many different foods, including ketchup, chili, and tacos, and are used in salads and in other popular dishes. Ethnic cuisines frequently contain tomatoes, such as Indian, Mexican, Italian, and others. While cooked foods containing tomatoes are not usually the cause of allergic symptoms, they can be in some people with this allergy.
According to the Anaphylaxis Organization of the U.K., most people with tomato allergy have only mild symptoms in the mouth which are caused by fresh tomatoes. Many people who are affected this way are not bothered at all by eating cooked tomatoes that are ingredients in foods.
Allergies and Food Processing
A research study that was completed in Italy in 2009 involved people who had a food allergy to tomatoes. They had been diagnosed from either their medical history or from an open food challenge. In this group, 23 people had mild symptoms that involved only reactions in their mouths. There were also 17 people who had allergic reactions to tomatoes that had been cooked. These were canned and peeled tomatoes and tomato puree. Tests showed that they were responding to the lipid transfer protein in this food product.
Symptoms of Tomato Allergy
Some of the symptoms that can occur from a tomato allergy are hives, eczema, skin rash, stomach cramps, nausea, vomiting, and diarrhea. These symptoms usually occur not long after eating tomatoes. Some people get an itchy feeling in the throat, coughing, sneezing, wheezing, or a runny nose. Others have swelling of the face, mouth, tongue, or throat. It is possible to have anaphylaxis from eating tomatoes, but this severe reaction is rare.
Some people with food allergies to tomatoes do develop eczema. This is not very common, and it is estimated that only about 10 percent of people with food allergies develop this skin condition. They may have rashes, itching, redness, and swelling if eczema does develop. Your allergist can test you to see if you have the IgE immunoglobulin in your body. This indicates that you do have a tomato allergy and will need to avoid tomatoes and all products that contain this fruit. Some people are able to eat tomato products if they take an antihistamine, but this should be done only after discussing your particular case with your doctor.