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

Red Currant Allergy Test: Allergen Exposure

The red currant is a member of the gooseberry family, native to parts of western Europe (Belgium, France, Germany, the Netherlands, northern Italy, and northern Spain).

There are many species of currants, the most common ones being red currant and black currant.

Currants are sometimes cultivated but often wild, and are found in many regions of the Northern Hemisphere. The red currant is similar to the black currant (or blackcurrant) but differs mainly in colour, being bright red or white.

It should not be confused with a small, seedless raisin which is also commonly called a ‘currant’, but is in fact a dried grape.

The red currant can be eaten fresh but is more often cooked in pies, jams, etc. It is a good source of vitamin C and potassium. Red currant is said to be depurative, digestive, diuretic, laxative, refrigerant and sialagogue. It is used cosmetically in face-masks.

The fresh leaves contain the toxin hydrogen cyanide which in excess can cause respiratory failure and even death.

Red Currant Allergy Test: Allergen Description

A lipid transfer protein (LTP) present in red currant has been identified.

Red Currant Allergy Test: Potential Cross-Reactivity

Extensive cross-reactivity among the different individual species of the genus including gooseberry and blackcurrant could be expected, but this possibility has not been explored. A lipid transfer protein (LTP) has been identified which may result in cross-reactivity with other LTP-containing foods.

Red Currant Allergy Test: Clinical Experience

Anecdotal evidence suggests that red currant may, in rare instances, induce symptoms of food allergy in sensitised individuals; however, few studies have been reported to date.

In one study, patients with a history of food hypersensitivity were asked to fill out a questionnaire in which 86 different foodstuffs were listed. ‘Slight symptoms’ were most common with (among others) red currant, which was the 49th-most-reported food resulting in adverse effects, affecting 9.2% of 1 139 individuals.

In a rare case of anaphylaxis, a 47-year-old woman presented with generalised urticaria, dysphagia, dyspnoea, pruritis of the palms and soles, hyptonia, and tachycardia, 2.5 hours after eating red currants. A month later, she developed generalised urticaria after eating black-currant jam.

A study reported on a 50-year-old woman with allergy to grass pollen and oral allergy syndrome involving several fruits. She presented with pruritus and pharyngeal occupation with dysphagia, while eating fresh red and black currant jam. She reported similar episodes with peach, apricot, and nectarine (jam, juice, and fresh). She tolerated other fruits of the Rosaceae family (i.e. raspberry, plum, apple, and pear).