Plum Allergy Test
Latin name: Prunus domestica
Source material: Fresh fruit
Common names: Plum, Gage, Prune
Plum is a food which may rarely result in allergy symptoms in sensitised individuals.
Plum Allergy Test: Allergen Exposure
The plum is a medium sized fruit containing a single stone. Colours vary according to the specific variety, of which there are around 2,000, ranging from red to yellow, blue or green. The most common variety is a purple to black colour.
Plums are cultivated widely across the globe, and are eaten fresh as well as being an ingredient in various jams, preserves, pastries, puddings and desserts. They are also commonly dried, after which they are known as prunes. Prunes are valued as a source of nutrition and also a digestive aid, having some laxative effect.
Plum Allergy Test: Allergen Description
Various allergens present in plums have been characterised, including a lipid transfer protein, a thaumatin-like protein and a profilin.
The lipid transfer protein tends to concentrate in the skin of Rosaceae fruits; in plum, it predominates as a cell-surface-exposed allergen.
Plum Allergy Test: Potential Cross-Reactivity
Extensive cross-reactivity between the fruit of the different individual members of the Rosaceae family occurs. Plum, cherry, apricot and peach allergens show overlapping but non-identical specificity.
The lipid transfer protein present in plum is highly homologous to the major allergen of peach and may result in cross-reactivity with other LTP-containing foods such as the LTPs of Rosaceae fruits (peach, apricot, cherry, plum and apple).
This cross-reactivity is not necessarily accompanied by cross-allergenicity to the corresponding fruits and elimination diets that rely on total avoidance of a group of foods, or only on the results of allergy testing, may result in unnecessary restriction of foods such as plum.
Allergy to plum has occasionally been reported to be associated with latex allergy.
Plum Allergy Test: Clinical Experience
Plum may induce symptoms of food allergy in sensitised individuals. Oral allergy syndrome (OAS) is the most often reported symptom to plum. OAS to fruits from the genus Prunus (plum, cherry, apricot, and peach) has been described as a cluster of hypersensitivities and occurs mostly as a result of the presence of a profilin.
As a result of the presence of profilin and lipid transfer proteins, adverse reactions to plum will vary according to geographical locality; for example, severe reactions from lipid transfer protein being more common in Southern Europe, and milder symptoms as a result of profilin being more common in Northern Europe.
It has been suggested that skin-prick tests with commercial extracts of plum and walnut may be usefully employed to detect patients with OAS reacting against allergens.
Anaphylaxis to plum has been reported. Severe adverse reactions to plum may commonly occur as a result of the presence of a lipid transfer protein.
A 32-year-old nurse with latex allergy experienced anaphylactic reactions following the ingestion of several members of the stone fruit family (plum, peach, and nectarine). Within 30 minutes of ingestion of fresh plum, she began to experience vaginal pruritus, generalised erythema, facial swelling, shortness of breath, and the sensation of tightening in her throat.
LTP may induce sensitisation via the respiratory tract due to inhalation of air-dispersed food particles, and that this may precede the onset of food allergy; studies have suggested that individuals are at risk where high levels of airborne LTP exposure may occur.