Pear Allergy Test
Latin name: Pyrus communis
Source material: Peel from fresh fruit
Pear is a food which may result in allergy symptoms in sensitised individuals.
Pear Allergy Test: Allergen Exposure
Pear is a fruit produced by a medium sized tree growing originally in western Asia and eastern Europe, but now found in in coastal and mildly temperate regions, from Western Europe to North Africa and right across Asia. Several thousand varieties are known.
The pear is a member of the same family as the apple, peach and apricot, and is very similar to the apple in cultivation, propagation and pollination.
The fruit varies in size from 1-8 cm in diameter and up to 18 cm in length. The most commonly recognised shape is the pyriform – known as “pear shaped”, however oblate and rounded variants exist.
Pears may be eaten raw or cooked, or may be used for the manufacture of alcoholic beverages such as Perry (a type of alcoholic cider).
Pear Allergy Test: Allergen Description
A number of allergens found in pear have been characterised, including a lipid transfer protein, a profilin and an an isoflavone reductase.
A study reported that peels of Rosaceae fruits such as apple, peach, and pear have a higher allergenicity than the pulps. In 33 patients allergic to these fruits, adverse reactions were reported to appear more frequently and to be more severe when the whole fruit was eaten. More than 40% of patients allergic to apple and pear tolerated the ingestion of the pulp of these fruits, and reactions were elicited only by the intake of the whole fruit.
Pear Allergy Test: Potential Cross-Reactivity
Foods belonging to the order Rosacea – which includes apple, pear, peach and almond – most commonly cause symptoms in birch-allergic patients.
In areas where birch pollen is an important aeroallergen, there is an association between spring pollen allergy and allergy to pear and apple.
Cross-reactivity may occur with other foods containing a similar isoflavone reductase, e.g. pea, orange, and banana.
In a study of 59 subjects 2 to 40 years old with spina bifida, latex sensitisation was present in 25%. Allergy to pear and kiwi were significantly associated with latex sensitisation.
Pear Allergy Test: Clinical Experience
Pear may result in symptoms of food allergy, anaphylaxis, and in particular oral allergy syndrome (OAS), in sensitised individuals.
In an Italian study of OAS in patients suffering from pollen allergy and allergic reactions after eating fruits and/or vegetables, allergy to pear was detected in 22%.
Allergy to Rosaceae fruits in patients with a related pollen allergy, usually to birch pollen, is often expressed as OAS. However, allergy to Rosaceae fruits in patients without a related pollen allergy tends to be a severe clinical entity. In such cases, the disease is often severe, generally with systemic reactions and a high frequency of anaphylaxis.
Anaphylaxis and food-dependent, exercise-induced anaphylaxis to pear has been reported.
A 20-year-old women who experienced anaphylaxis to string bean also reported urticaria from ingesting fresh fennel, boiled cabbage, mustard, hazelnut cream and commercial pear juice.
Occupational contact urticaria and contact dermatitis to pear have been reported.
Ingestion of pear fruit juice may result in chronic, non-specific diarrhoea in infancy and childhood.
Pear and Japanese pear (P. pyrifolia) pollen may result in asthma and rhinoconjunctivitis in sensitised individuals.