Tea Allergy Test
Latin name: Camellia sinensis
Source material: Tea leaves
Common names: Tea, Black Tea, Green Tea, Oolong tea
Tea is a food which may result in allergy symptoms in sensitised individuals.
Tea Allergy Test: Allergen Exposure
Tea is a common beverage consumed around the world, and is prepared by steeping or boiling tea leaves in water. The Tea plant is a member of the Theaceae family and is a tropical and subtropical evergreen shrub or tree, which has been cultivated for over 5,000 years, originally in China.
The hundreds of varieties of Tea plants, each with its distinctive leaves, grow from the same species but in many different environments in about 30 countries. However, all Tea plants are essentially the same, particularly in that the dry leaves contain 3-6% caffeine, which is responsible for the stimulating effect of the beverage. The largest differences between the end products are due to the methods of preparation.
Black tea, the kind that is by far the most popular worldwide and in the West, comes from leaves that have been fermented before being heated and dried. Green tea is prepared from fresh leaves. Oolong tea is a partially oxidised product.
Although Black tea flavours vary, most are stronger than those of Green or Oolong teas. Among the better known Black teas are Darjeeling, English breakfast and Lapsang Souchong. Earl Grey tea is a Black tea treated with oil of bergamot, which gives it a characteristic taste.
Tea is available commercially mainly in tea bags and as loose fragmented or whole leaves. In East Asia, tea tends to be served plain, but from India to the West additives can include spices, sugar, milk, cream, lemon and other fruit. Iced teas are made hot but served chilled, sometimes with added flavours.
Green tea polyphenols have demonstrated significant antioxidant, anticarcinogenic, anti-inflammatory, thermogenic, probiotic, and antimicrobial properties. Tea is a rich source of fluoride but reduces the absorption of iron from food.
Tea Allergy Test: Allergen Description
No allergens from this plant have yet been characterised.
A component of green tea leaves is reported to be a causative agent in occupational tea-induced asthma (from inhalation of green tea dust).
Tea Allergy Test: Potential Cross-Reactivity
Extensive cross-reactivity among the different individual species of the genus could be expected but has not been documented in the literature.
Tea Allergy Test: Clinical Experience
Tea may uncommonly induce symptoms of food allergy in sensitised individuals, but is more commonly associated with occupational asthma resulting from the inhalation of tea dust. Chronic tea dust exposure has been reported to increase the prevalence of respiratory symptoms and can result in a significant degree of small airway obstruction in tea workers.
Tea may increase the risk of bleeding or potentiate the effects of warfarin therapy.
Repeated muscle cramps and distal paraesthesias in all limbs, and a feeling of pressure in the eyes, associated with blurred vision, particularly in darkness, were reported in a 44-year-old male drinking more than 4 litres of Tea per day.
Tea contains caffeine, which may result in adverse symptoms in certain individuals who either drink excess amounts of caffeine or are intolerant to caffeine, including irritability, tachycardia, chronic headaches, urticaria and anaphylaxis.