Food Allergies to Tomato Sauce

As a popular base for soups, stews, pasta, pizza and other dishes, tomato sauce appears on nearly every restaurant and family menu. You can be allergic to any kind of food, but most food allergies involve an immune reaction to the proteins in milk, soy, nuts, fish, shellfish, eggs and wheat. Allergic responses to tomatoes usually are mild but some factors may exaggerate the reaction, leading to more severe and even dangerous symptoms. If you suspect you are allergic to tomatoes or tomato sauce, consult a doctor.

Allergic reactions to fruits and vegetables usually involve mild, mouth-related symptoms, including itching and hives or a rash around the mouth, according to a May 2009 Medical News Today article. Other symptoms associated with food allergies include swollen lips, tongue, face or throat; cramping and nausea; lightheadedness; or, more rarely, a severe and life-threatening reaction called anaphylaxis. Signs of anaphylaxis may include tightness of the airway, rapid heartbeat, drop in blood pressure, dizziness, fainting, shock and even death. If you suspect you are having an anaphylactic reaction, seek immediate medical attention. Note that food allergy symptoms usually develop less than an hour after ingestion. Exercising or drinking alcohol during or after eating may exaggerate a food allergic reaction.

A study appearing in the "Journal of Agricultural and Food Chemistry" reports that the skins, pulp and seeds of fresh tomatoes contain several different allergens; one of these -- called lipid transfer protein, or LTP -- was also identified in cooked, commercially prepared tomato sauces. This means cooking, which often eliminates or reduces the amount of allergens of some fruits and vegetables, does not entirely eliminate the allergens in tomatoes. Some people are allergic only to fresh tomatoes, while those allergic to the LTP allergen may be allergic to both fresh and cooked tomatoes. Note also that the riper the tomato, the higher the concentration of allergens in the tomato.

Many people who get hay fever also experience allergic reactions to plant-based foods. Called pollen-food allergy syndrome, this often severe reaction may involve swelling of the throat or even anaphylaxis. This is considered a cross-reactivity, meaning the two sets of proteins are related enough to cause people to experience allergic reactions to both. Those allergic to peanuts, ragweed pollen or grass pollen may also react to tomatoes.

According to the University of Hawaii Department of Pediatrics, about 30 to 50 percent of people with latex allergies also react to certain fruits and vegetables. These may include almonds, apples, hazelnut, melons, papaya, pears, carrots, celery, bananas, avocados, chestnuts, kiwi, peaches, potatoes -- and tomatoes. This condition is called latex-fruit syndrome. Note that latex allergic reactions can prove fatal, usually beginning with a skin reaction due to exposure and sometimes progressing to anaphylaxis. Consult a doctor for advice.

A reaction to commercially prepared tomato sauce does not always indicate a tomato allergy. Check the ingredient label; some tomato sauces -- especially flavored pasta sauces -- may contain products derived from milk or soy, two of the most common sources of food allergens.

If you suspect you have food allergies, see a doctor to determine which ones and receive advice on treatment. If you are allergic to tomatoes, your doctor will probably suggest that you avoid eating them. Besides avoiding the fresh tomato in the produce aisle, also read ingredient labels to make sure the food causing your allergy is not listed there. Your doctor may also recommend that you be cautious about exposure to associated allergens, including peanuts, ragweed pollen, grass pollen and latex. For mild reactions, your doctor may recommend over-the-counter antihistamines or ointments. A history of severe reactions may require you to carry epinephrine, a prescription-only medicine for treating anaphlyaxis.