Lemon Allergy Test
Latin name: Citrus limon
Source material: Fresh fruit
Lemon Allergy Test: Allergen Exposure
Lemons are thought to have originated in India, although the precise origins are unknown. They are now cultivated and consumed extensively around the globe, with the largest producers being India, Mexico, China, Argentina and Brazil. Lemons for export may be harvested early and naturally ‘cured’ in transit.
The fruit is oval and around 7 to 12 cm long, with a nipple-like protuberance at the apex. Most variants are pale to moderate yellow, although some cultivars have green or white longitudinal stripes. The peel is thick, tough and contains a high proportion of aromatic oil.
The fruit is used primarily for its juice, though the pulp and rind (‘zest’) are also used, primarily in cooking and baking to add flavour to baked goods, puddings, rice and other dishes. Lemon juice is about 5% citric acid, which gives lemons a tart taste.
Whole lemons can be used in the manufacture of preserves and marmalades, while the juice is used for drinks including lemonade, soft drinks and as a garnish in cocktails. The acidity of the juice makes it an ideal marinade for tenderizing fish and meat, as well as a short term preservative, preventing foods such as apple, banana and avocado from discolouring in the presence of air.
Lemons can be preserved in jars or barrels of salt, which cures them to a point that they can last almost indefinitely. These preserved fruits are commonly found in Morroccan, Sicilian, Italian, Greek, and French cuisine.
Oils from the skin are used in perfume-making, and the juice and peel have a range of applications as a cleaning agent, solvent, polish and disinfectant.
Lemon Allergy Test: Allergen Description
Allergens present in lemon which have been characterised include a germin-like protein, as well as a lipid transfer protein.
Lemon Allergy Test: Potential Cross-Reactivity
Cross-reactivity within the Rutaceae family (lemon, lime, orange, tangelo, grapefruit) can be expected, but has not been documented to date.
Both orange and lemon lipid transfer protein has been shown to display cross-reactivity with the major peach lipid transfer protein.
Lemon Allergy Test: Clinical Experience
Ingestion of lemon may result in allergic reactions, including food allergy, allergic rhinoconjunctivitis, atopic dermatitis and anaphylaxis. Lemon-dependent, exercise-induced anaphylaxis has been reported.
In one case a 26-year-old peanut-allergic man exhibited sensitivity to citrus seed and experienced anaphylaxis to lemon soap, after showering and washing his torso and face with lemon-impregnated soap. Symptoms included laryngeal oedema, generalised urticaria, and asthma, and occurred within minutes of ingestion.
In a study aimed at characterising raspberry allergens, a 25-year-old patient was described who had experienced periorbital oedema and rhinitis from lemon and other citrus fruit.
Eosinophilic gastroenteritis and urticaria following ingestion of citrus fruit was described in a 46-year-old male, who presented with a 2-month history of non-bloody, frequent, loose bowel movements, with abdominal cramping and nausea without emesis.
Importantly, individuals allergic to lemon, mandarin or other citrus fruit may not necessarily be allergic to all citrus fruits.
Lemon contact with human skin may result in adverse skin reactions such as phytophotodermatitis.