Lips tingling after a korma, or hives after a vegan cheesecake? Cashew turns up in far more foods than the nut bowl, often ground into sauces where you cannot see it. Our test checks your blood for IgE antibodies to three single cashew proteins, as part of 300 allergens and allergen components, so you can see whether you are sensitised to cashew and to which proteins.
The cashew proteins that matter for allergy are storage proteins. Lab tests call them Ana o 1 (a vicilin), Ana o 2 (a legumin) and Ana o 3 (a 2S albumin). All three are stable to heat, so roasting does not make cashew less of a concern for people who react to it.
Of the three, Ana o 3 is the one specialists look at first. Studies in children found that IgE to Ana o 3 tells real cashew allergy apart from harmless sensitisation better than a whole-cashew test does. Cashew has no birch-like protein that explains mild, pollen-related reactions the way hazelnut does.
People describe itching in the mouth, swollen lips or eyes, hives, stomach pain or vomiting, often within minutes of eating cashew. Some report wheezing or feeling faint. Reactions to small amounts, such as a sauce with ground cashew, are commonly described.
Swelling of the lips, tongue or throat, trouble breathing or feeling faint after eating is an emergency. Call 112 (EU) or your local emergency number. Do not wait for a test.
Cashew and pistachio come from the same plant family, and their storage proteins are very alike. Studies find that most people with cashew allergy also react to pistachio. That makes the pair one of the clearest links among tree nuts.
A positive result shows sensitisation, not that you will react. Some people have IgE to cashew and eat it without trouble. If you have never reacted, do not cut cashew out on a result alone. If you have, take the result to a doctor or allergist.
The lab measures IgE to three single cashew proteins (molecular components). There is no whole cashew extract on the panel. Your lab report gives each a measured value and class, from Negative to Very high, next to pistachio, the other tree nuts and peanut. Treat it as a pattern to discuss with your doctor, not a diet plan.
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One finger-prick sample checks IgE to 300 allergens and allergen components, from birch and peanut to cat and house dust mite. Post it to the lab, and about 5 days after it arrives you get a value for every one. Our plain-English guide shows you how to read them. €399 in total, €1.33 per allergen.
Often, the two go together. Cashew and pistachio share very similar proteins, and studies find most people with cashew allergy also react to pistachio. Your report shows both separately, so a doctor can look at the pattern.
Not usually. The main cashew allergens are storage proteins that stay stable when heated. Roasted, raw or ground into a sauce, the proteins are still there.
It shows IgE to a cashew 2S albumin. Studies in children found it is the most useful single marker for telling cashew allergy apart from harmless sensitisation. It is still not a diagnosis. A doctor reads it with your history.
Botanically it is a seed of the cashew apple. For food labels and allergy it counts as a tree nut, and EU law requires it to be declared on packaged food.
