Tomato is a food which may result in allergy symptoms in sensitised individuals.

Tomato Allergy Test: Allergen Exposure

Originating in South America the tomato is believed to have first been cultivated by the indigenous peoples of what is now Mexico. Spanish explorers brought the tomato back to Spain in the 16th century from where its use spread to other European countries.

The tomato is consumed in diverse ways, raw or cooked, in many dishes, sauces, salads, and drinks. While tomatoes are fruits, botanically classified as berries, they are commonly used as a vegetable ingredient or side dish.

The tomato fruit can also be dried and ground into a powder to serve as a flavouring and thickening agent in soups, breads, pancakes, and so on. An edible oil can be obtained from the seed. The fruit is rich in vitamins A and C, calcium and potassium, and the skin is an excellent source of lycopene.

Tomato is used as a herbal remedy for a variety of conditions. The pulped fruit is a wash for oily skin. The oil can be used in making soap.

The leaves, stems and other green parts of the plant are poisonous, and tomato leaf extract is used in the production of insecticide.

Tomato Allergy Test: Allergen Description

Allergens present in tomato began to be isolated around 4 decades ago but have only recently been characterised. In total, 8 allergens have been characterised including a profilin, a beta-fructofuranosidase, a lipid transfer protein and a pectin methylesterase inhibitor.

Specific allergens may be involved in specific adverse reactions.

The allergenicity of Tomato appears to be influenced by hormone treatment of the fruit with ethylene and salicylic acid.

Tomato Allergy Test: Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the genus could be expected, as well as to a certain degree among members of the family Solanaceae, and this has been demonstrated.

Studies have reported an association between grass pollinosis and sensitisation to tomato, potato, green pea, peanut, watermelon, melon, apple, orange and kiwi.

The lipid transfer protein (LTP) panallergen in tomato may result in cross-reactions with other foods containing this panallergen, e.g., Rosaceae fruit, tree nuts, peanut, beer, maize, mustard, asparagus, grape, mulberry, cabbage, date, orange, fig, kiwi, lupine, fennel, celery, eggplant, lettuce, chestnut and pineapple.

Tomato also contains a 1,3-beta-glucanase, which may result in cross-reactivity with other foods or plants containing this panallergen, e.g., potato, bell pepper, banana, latex and olive tree pollen.

Tomato Allergy Test: Clinical Experience

Tomato is a common cause of symptoms of food allergy in sensitised individuals.

Allergic manifestations to tomato include urticaria/angioedema, dermatitis, perioral dermatitis, oral allergy syndrome, asthma, rhinitis, and abdominal pain. Tomato pollen may trigger rhinitis and/or conjunctivitis.

However, although tomato is a commonly consumed food, severe allergic reactions to Tomato are unusual or rarely reported.

Food-dependant exercise-induced anaphylaxis has also been commonly reported.

Tomato has also been associated with eosinophilic oesophagitis.

Other reactions

Auriculotemporal syndrome (or gustatory flushing syndrome), has been reported to masquerade as food allergy (erythema alone) following ingestion of spicy food such as Tomato sauce.

Tomato has also been implicated as a factor in irritable bowel syndrome.