"Cashew nuts present a considerable hazard, being hidden in a wide variety of commonly ingested foods, such as Asian meals, sweets, ice cream, cakes, chocolates and they are increasingly used in commercially prepared pesto sauce instead of pine nuts," wrote lead author Andrew Clark in the journal Allergy . "
Specific information on how to achieve nut avoidance should always be provided," he added.
An estimated 4 per cent of adults and 8 per cent of children in the 380 million EU population suffer from food allergies, according to the European Federation of Allergy and Airways Diseases Patients' Associations.
There is no current cure for a food allergy, and vigilance by an allergic individual is the only way to prevent a reaction.
But a peanut allergy can be so severe that only very tiny amounts can be enough to trigger a response.
While cashews are used less extensively as ingredient than peanuts, the new study suggests that the allergic reaction to the former may be more severe than even that of peanuts.
The researchers, from Addenbrookes Hospital (Cambridge University Hospitals) and Queen Elizabeth Hospital, Kings Lynn, matched children whose worst ever reaction was to cashew nut (cashew group, 47 children) with children whose worst ever reaction was to peanut (peanut group, 94 children).
The comparison matched the children according to sex, age of reaction and presentation, amount ingested, and asthma.
"This is the first study to employ case-matching to compare severity of peanut and cashew nut allergy and demonstrates increased severity of reactions to cashew nut," said Clark.
The researchers note that wheezing and cardiovascular symptoms were reported more often during reactions in the cashew than compared to the peanut group, while those allergic to cashews also received intramuscular adrenaline more frequently. "
A recent study showed that 10/37 (27 per cent) of nut-allergic children were unable to correctly identify the type of nut to which they were allergic," wrote the researchers.
"Previous studies show cashew nut can cause severe reactions.
The nut type which caused the worst reaction to date should be considered when providing emergency medication," they concluded.
Source: Allergy (Blackwell Publishing) Volume 62, Issue 8, Pages 913-916 "Cashew nut causes more severe reactions than peanut: case-matched comparison in 141 children" Authors: A. T. Clark, K. Anagnostou, P. W. Ewan